- A new report is the latest to bolster long-standing allegations that many long-tailed macaques imported into the U.S. for biomedical research were illegally caught from the wild and falsely labeled as captive-bred, with suspiciously high birth rates at breeding facilities in Southeast Asia.
- Cambodia became a major supplier of monkeys for research after China stopped exports in 2020, but investigations found indications of large-scale monkey-laundering operations, leading to legal cases, failed prosecutions, and a 64% drop in exports by 2023. Despite concerns, global wildlife trade regulator CITES did not ban the trade.
- Vietnam’s reported monkey exports also show discrepancies, with new “satellite breeding facilities” appearing without proper documentation, raising concerns that wild monkeys are also being trafficked into breeding farms.
- A tuberculosis outbreak linked to Vietnamese monkey exports highlights the public health risks, while U.S. company Charles River Laboratories faces scrutiny over its alleged role in the illegal monkey trade, seeming to benefit from political ties to evade accountability.
BANGKOK — Many long-tailed macaques imported into the United States from Southeast Asia were likely poached from the wild and then sold as captive-bred to medical research institutions, a recent report alleges.
The 137-page report by Sandy River Research details “biologically impossible” birth rates at monkey-breeding facilities across Southeast Asia. It highlights contradictory claims made by these facilities about their capacities and uses calculations based on publicly available data regarding the export of monkeys, suggesting that wild monkeys are being caught, laundered at scale through the Mekong region’s breeding facilities, and then sold as captive-bred monkeys, mostly to U.S.-based researchers.
The report goes on to note how regulatory failures and a lack of due diligence has ensured that poachers, smugglers, breeding facilities and the biomedical research industry have found ways to profit at the expense of endangered long-tailed macaques (Macaca fascicularis).
The public health risks of wild-caught monkeys being shipped around the world not only heighten the risk of zoonotic diseases spreading, but also jeopardize the scientific integrity of any research based on the study of wild monkeys, the report added. The “unabated” poaching of long-tailed macaques across Southeast Asia has seen populations plummet, with multiple studies pointing to the demand created by the biomedical research industry as a key driver in the species’ decline in some Southeast Asian countries.
The report doesn’t list an author and Sandy River Research states on its website that it “will not offer further comment beyond what is stated in this report.” Mongabay has not been able to independently verify the identity of the report’s author, but the data presented are largely drawn from referenced publicly available sources.
Indeed, much of it comes from data submitted by Southeast Asian governments to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the United Nations-administered regulator of the wildlife trade.
China had long supplied the world’s laboratories with monkeys, but abruptly ceased exports in 2020 in response to the COVID-19 pandemic. Cambodia stepped in to fill the demand created by COVID-19 vaccine testing, with exports jumping more than 99% from 2019 to 2020, according to CITES data.
However, this sudden jump in Cambodia’s monkey exports prompted scrutiny, with the CITES Secretariat warning on Jan. 10, 2025, that it had “received credible information concerning the illegal export of specimens of wild caught [long-tailed macaques],” which indicated that as many as 50,000 wild monkeys had been laundered through just one of Cambodia’s eight breeding farms between 2019 and 2021.
Questionable Cambodian data
The Ministry of Agriculture, Forestry and Fisheries reported in September 2022 that Cambodia’s breeding facilities housed 137,359 long-tailed macaques and that 73,016 had been born in a single month. This is a significant increase given that the facilities’ entire population reported in December 2020 was just 69,215 monkeys. No farms were authorized to collect monkeys from the wild between 2014 and 2023, barring a handful of small exceptions, but the Sandy River Research report suggests that this expansion exceeds biologically feasible birth rates for the species and was only possible through laundering wild-caught monkeys into the farms, passing them off as captive-bred.
Cambodian exports for 2021 hit 48,160 live monkeys, followed by 37,920 in 2022, but that year an indictment from federal prosecutors in the U.S. accused a Cambodian breeding farm, Vanny Bio Research, of monkey laundering. The indictment named two senior Cambodian forestry officials and six individuals connected to Vanny Bio, alleging they belonged to a comprehensive smuggling ring that was plundering the nation’s forests of monkeys and selling them abroad.
Only Kry Masphal, one of the Cambodian officials named in the indictment, was arrested and tried before being ultimately acquitted in March 2023, but the trial uncovered a wide range of abuses in the Cambodian monkey trade, which saw exports fall by 64% to 13,305 in 2023.
While the U.S. Fish and Wildlife Service (USFWS) failed to secure a conviction in the case of Masphal, the agency took evidence accrued over the course of its five-year investigation in Cambodia to CITES. The CITES Secretariat in January 2025 recommended suspending the trade of Cambodian long-tailed macaques, citing suspiciously high birth rates among Cambodian monkey farms, where limited logbook keeping and genetic testing raised the risk that monkeys were being trafficked into the farms from the wild. Cambodian CITES officials strongly objected to the proposed ban, claiming data provided to CITES by USFWS had been obtained during Masphal’s arrest and shouldn’t be cited as official Cambodian data.
It proved not to matter because the CITES Standing Committee — made up of the world’s largest importers of Cambodian monkeys, including the U.S., Canada and Japan — rejected the Secretariat’s recommendation, allowing the trade to flourish, despite the irregularities that continue to pile up.
As such, the Sandy River Research report adds yet more weight to the arguments scientists, conservationists and activists have been making about the biomedical research industry.
Two Cambodian facilities focused on in the report include the K-F (Cambodia) farm in Kampong Thom province and the Orient-Cam farm in Kampong Chhnang province.
Breeding rates at both K-F and Orient-Cam were so high that the report concludes both companies must have been laundering wild-caught monkeys into their farms to explain the sudden spike in populations. The report calculates that, using K-F’s data, the farm would have exhausted their exportable supply of 18-month-old juvenile monkeys by 2020. Orient-Cam’s data suggested a breeding rate of 92% — meaning 92 offspring for every 100 female breeding monkeys — which CITES deemed impossible.
“There can be no dispute that the deficit has been filled by macaques obtained illegally and likely laundered into and out of the K-F site for export for many years,” the report reads. “These unimpeachable numbers further render Cambodia’s 2024 CITES response a farce.”
K-F and Orient-Cam didn’t respond to emailed questions sent by Mongabay and couldn’t be reached by phone numbers listed in government records.
Khim Finan, spokesperson for the Ministry of Agriculture, Forestry and Fisheries, told Mongabay via messaging app Telegram that the claims made by the Sandy River Research report are just allegations.
“The fact is that we prevailed in the U.S. court case regarding this same accusation, despite numerous articles containing claims and allegations,” Finan wrote in a message.
When asked whether he believed that Masphal not being convicted in the U.S. means there’s no monkey smuggling in Cambodian breeding facilities, Finan didn’t reply.
“Now it’s up to you and other news outlets whether you want to spread more unverified news and baseless claims/allegations against countries that are range states and parties to CITES, or recognize the facts and our efforts as a full party to CITES,” Finan wrote.
He couldn’t give reporters any specific claims or allegations made in the report that the ministry disagreed with, but assured Mongabay that the report had been read.
The CITES Secretariat declined to answer specific questions about irregularities at monkey farms across the region, but noted that it aimed to visit Cambodian farms to be able to report back on findings ahead of the November 2025 CITES conference in Uzbekistan.
‘They are rare now’
One monkey poacher, speaking on the condition of anonymity due to the criminal nature of his work, told Mongabay he’s been illegally trapping wild monkeys for more than five years in Cambodia’s eastern province of Kratie.
He detailed how he sold them to middlemen who sell the monkeys on again, mostly to breeding farms in Cambodia and, increasingly, over the border in Vietnam.
“For the past two months, I didn’t see monkeys, they are rare now,” the poacher said in a phone interview. “In January, my cousin caught two monkeys. When they walked in the forest, they saw monkeys, they then started to cut the surrounding trees and laid the nets. They then called the regular buyers in Kratie to come and take them. They loaded [the monkeys] inside the motorbike seats.”
The monkeys, seemingly caught in Prey Lang Wildlife Sanctuary, sold for 100,000 riel (roughly $25) and weighed around 3 kilograms (6.6 pounds). Smaller monkeys in good health can fetch up to $50, the poacher told Mongabay, noting that young female monkeys are the most prized catches.
Prices fell from roughly $150 in 2022 to $50 in 2024 as scrutiny of Cambodia’s monkey trade saw exports plummet in 2023, but compounding this, the poacher said monkeys aren’t as abundant as three years ago.
The poacher told Mongabay he had never been caught transporting monkeys from the wild. The middlemen would come to his house, sometimes once a week, to purchase the monkeys he caught. The poacher alleged that middlemen often carried large sums of money, as much as $2,000, which he said was to bribe authorities if they were stopped while transporting the monkeys to Cambodian and Vietnamese breeding farms.
“The price is now cheap. If we caught female monkeys, they [middlemen] would be interested in buying them,” he said. “I don’t know for sure; they might be [smuggling] monkeys to Vietnam. Mostly, monkeys are transported to Vietnam.”
Signs of trafficking to ‘secret’ farms in Vietnam
The Sandy River Research report also brought into sharp focus the anomalies that have been piling up in Vietnam’s monkey trade, where yet more data discrepancies point to the laundering of wild monkeys.
Since 2014, Vietnam has only ever declared four breeding facilities from which it exports long-tailed macaques. However, in October 2024, Vietnamese authorities told CITES about the existence of so-called “satellite breeding facilities.”
These satellite monkey farms don’t export directly, but appear to supply long-tailed macaques to the four licensed exporting farms. In 2023, Vietnam told CITES that, since 2019, exporting farms had received 3,727 long-tailed macaques from previously undisclosed “legal domestic breeding facilities.”
But when responding to CITES in October 2024, the number of monkeys provided by the satellite farms between 2019 and 2023 had jumped to 13,426 — a steep rise that prompted CITES to pry further.
CITES requested Vietnam provide the number of satellite farms, how long they’d been operating, how many monkeys they produced, and how they were inspected. Yet when Vietnamese authorities responded in January 2025, they only provided the 11 provinces in which the satellite farms are located and the total stock of monkeys in each, omitting key data points needed for regulatory oversight.
Vietnamese CITES representatives didn’t respond to emailed questions sent by Mongabay regarding the country’s long-tailed macaque trade.
Pablo Fernández of Spain-based activism group Abolición Vivisección told Mongabay in a phone interview that the opaque trade of long-tailed macaques between Cambodia and Vietnam is very common and flows in both directions, likely with political connections facilitating paperwork.
Vietnam, Fernández said, may be heading in the same direction as Cambodia now that exports are increasing. And so while there may be increased scrutiny from CITES, he warned there will also be more interest in preserving the trade.
These interests stem from international buyers, largely within the biomedical research sector, who wield immense influence owing to the vast profits associated with their work.
Global demand
While monkeys may sell on the ground in Cambodia for hundreds of dollars, they’re worth thousands to laboratories across the U.S. and Canada. The industry has proven highly resilient in the face of mounting scandals that have been exposed through the Southeast Asian supply chain of monkeys.
The U.S. Centers for Disease Control (CDC) reported no known cases of tuberculosis in “non-human primates” imported to the U.S. since 2013. But in February 2023, the CDC reported that a shipment of 540 long-tailed macaques from an unnamed country in Southeast Asia was contaminated with Mycobacterium orygis, the bacteria that causes tuberculosis in humans.
One bill of lading from Thanh Cong Jingang Biological Technology in Vietnam’s Lang Son province shows the company exported 540 long-tailed macaques, valued at $3.1 million, to Charles River Laboratories in the U.S. on Jan. 11, 2023. No other shipment from Vietnam matches the details released by the CDC, suggesting that Thanh Cong shipped monkeys with what People for the Ethical Treatment of Animals (PETA) described as “a highly infectious [tuberculosis] strain that has never been seen in animals in the U.S.”
At least 34 of the 540 monkeys had to be euthanized, but the prevalence of novel TB strains in monkeys sold by Thanh Cong Jingang, coupled with the farm’s unusually high mortality rates calculated in the Sandy River Research report, suggest the company has been supplementing its farms with wild-caught monkeys.
The company, headed by Nguyen Thanh Cong since 2006, was fined 300 million Vietnamese dong (roughly $12,000) in 2020 for failing to produce an environmental impact assessment, which is required by Vietnamese law for any facility with more than 50 wild animals.
According to the Sandy River Research report, Thanh Cong Jingang told CITES in 2023 that it had 784 monkeys in its breeding stock as of 2019, although when questioned further on this, the company revised its numbers, telling CITES in 2024 that it actually had 1,588 breeding monkeys in 2019. Similarly, a 500-monkey difference can be seen between the company’s reported 2023 breeding stocks in responses sent to CITES in 2023 and 2024.
Geraldine Fleurie, senior director of global nonhuman primate supply management at Charles River Laboratories, can be seen briefly in a promotional video for Thanh Cong Jingang from 2024. Charles River Laboratories has long been accused of profiting from Southeast Asia’s alleged monkey-laundering operations and was subpoenaed by the U.S. Department of Justice in 2023 in relation to its Cambodian supply chain.
Thanh Cong Jingang could not be reached for comment, while a spokesperson for Charles River Laboratories initially told Mongabay they would answer questions sent by email, although no response was received as of press time.
However, while Charles River Laboratories has remained silent, the company did publish its 2025 nonhuman primate (NHP) report, seemingly in late March, and only the second of its kind from the company. The report details Charles River Laboratories’ commitment to compliance issues and its opposition to illegal trade, and notes that “international developments have called certain aspects of the global NHP supply chain into question.”
While Charles River Laboratories claims to have developed a highly successful means for genetic testing, which would help to eliminate trafficked monkeys from its supply chain, the 2025 report states “genetic testing methods will take time, resources and international regulatory and supplier cooperation to fully implement at scale.”
The company writes that it puts all monkey suppliers through “enhanced due diligence, documentation, monitoring and auditing,” including monitoring of “adverse media.” But with the exception of Noveprim in Mauritius, the report doesn’t list the breeding farms from which it buys long-tailed macaques. The company declined to answer specific questions sent by Mongabay regarding its relationships with K-F (Cambodia) and Orient-Cam in Cambodia, as well as Thanh Cong Jingang in Vietnam, which is suspected to have supplied diseased monkeys to Charles River Laboratories in 2023.
Charles River Laboratories’ 2025 report does mention the risk of zoonotic diseases, but neglects to mention the 2023 outbreak seemingly linked to its supply chain. Instead, the company dismisses the matter “as the alarmist claims of animal rights activists.” Notably, the company also claims to have invested “millions” in alternatives to monkeys that animal rights groups have long called on the biomedical research industry to transition toward.
Lisa Jones-Engel, a primate scientist with PETA, said in an email that “Charles River Laboratories has so far evaded real consequences for its role in a transnational criminal network that illegally sources wild primates for the violent and corrupt international primate trade — an industry fueled by money, illicit wildlife trafficking, fraud, and the suffering of thousands of monkeys.”
Jones-Engel suggested this was made possible due to the biomedical research industry’s political ties in the U.S. and shared documents detailing how Margaret Everson, a former Department of Interior official and USFWS employee was attempting to influence the USFWS in favor of the biomedical research industry through her lobbying firm Mill Run Strategies.
She noted that 1,269 long-tailed macaques found to be illegally imported from Cambodia to Charles River Laboratories have not been released into sanctuaries, despite evidence they were trafficked.
“The real question isn’t just how Charles River has gotten away with this, but why the U.S. government continues to let them,” she said.
Banner image: An endangered long-tailed macaque peeks out from a cage having been exported from Vietnam to Europe. Image supplied by Animal Rights BE.