NEWS20 July 2026Other researchers say that non-infectious viral samples in luggage posed no risk, but might have violated import rules.ByDan Garisto0Dan GaristoDan Garisto is a freelance reporter in Syracuse, New York.View author publicationsSearch author on: PubMed Google ScholarTwo scientists at the Rocky Mountain Laboratories in Hamilton, Montana, have been charged in connection with biological material they brought into the United States from abroad.Credit: PBH Images/AlamyTwo virologists at the US National Institutes of Health (NIH) are facing charges related to the alleged smuggling of non-infectious monkeypox virus (MPXV) and other biological samples into the United States, in a case that has become a flashpoint for legal and political concerns around biosecurity.The charges centre on samples that NIH scientists Vincent Munster and Claude Kwe were carrying when they arrived in Detroit, Michigan, in January after doing research in the Republic of the Congo. Samples tested by the US Federal Bureau of Investigations as of 29 May contained MPXV DNA, according to a criminal complaint, but none were infectious. Such samples do not require an import permit but must be declared to federal officials.Arrests of scientists over smuggled samples add to US border anxietyAccording to the complaint, which was brought by the US Department of Justice, Munster and Kwe allegedly failed to declare the samples and then lied to officials about them. Both scientists have pleaded not guilty. Benton Martin, a federal community defender representing Kwe, who had his initial hearing last month, said that his client “is presumed innocent and we will await future proceedings before commenting further.” An attorney for Munster, who is scheduled to appear at an initial hearing 22 July, did not respond to a request for comment.The case is the latest in a string of prosecutions of researchers for smuggling biological samples. It has brought additional scrutiny to Munster and Kwe’s workplace, the NIH’s Rocky Mountain Lab (RML), in Hamilton, Montana, and to the import of pathogens for study. The RML declined to comment, and a spokesperson for the Department of Health and Human Services, which oversees the NIH, declined to provide additional comment because the case is ongoing.Members of Congress have sought an investigation of the lab and introduced legislation to impose severe sentences for smuggling biological agents. “Illegally smuggling dangerous viruses into our country threatens the health and safety of all Americans,” Senator Tom Cotton, a Republican from Arkansas, said in a statement.Monkeypox virus (green, artificially coloured) causes the disease mpox.Credit: NIAID/National Institutes of Health/Science Photo LibrarySome scientists have defended the pair, and argue they did nothing dangerous.Angela Rasmussen, a virologist at the University of Saskatchewan in Canada, noted that inactivating viruses with potent chemicals is a reliable way to render them inert. “You could drink them and not get infected,” she wrote in a blog post.Other researchers agree that inactivated samples pose no risk, and acknowledge the logistical difficulty of moving samples. But “the regulations have to be followed,” says Melanie Ott, a virologist and head of the Gladstone Institutes in San Francisco, California. “The virology community is not standing for taking shortcuts.”Virus trackersMunster, who is the head of the virus ecology section at the National Institute of Allergy and Infectious Diseases (NIAID), is a leading virologist who has spent decades tracking viruses such Ebola1 and more recently, a new strain of MPXV2. In 2020, Munster and Emmie de Wit, an RML virologist who is married to Munster, won a Golden Goose award, which honours obscure research that proves beneficial: they studied coronaviruses in camels3for years before parlaying their work into research on antiviral treatments for COVID-19.In January, Munster and Kwe did nine days of field work in Congo. When they tried to re-enter the United States, Munster “adamantly denied any biological materials or samples,” according to the federal complaint, and said that he and Kwe were carrying diagnostics. Inactivated MPXV is considered a biological material under import law, but samples of it are used for diagnostics.Growing mpox outbreak prompts WHO to declare global health emergencyThe FBI complaint says repeatedly that the men’s luggage contained “deactivated monkeypox virus.” It also states, “Munster and Kwe did not present the true identities of the biological materials in their possession and did not provide or possess the necessary certifications. Rather, Munster and Kwe attempted to pass the samples off as unused diagnostics.” Inactivated viral samples also require a certification of deactivation. Munster, who designed protocols to inactivate MPXV4, allegedly told border control the required documents were on his laptop, but the complaint does not make clear whether that was the case.Email cacheOn 5 June, Rand Paul, a Republican senator from Kentucky, released dozens of pages of emails between Munster and other scientists about the handling of biological samples. Paul, a frequent critic of former NIAID director Anthony Fauci and a number of other virologists, claims that the correspondence shows a pattern of violations by Munster. In one set of emails from 2011, another researcher suggests Munster could “hand carry” viral samples on a commercial flight. The emails do not say whether Munster did so.Jean-Paul Gonzalez, a virologist and biosecurity specialist at Georgetown University in Washington DC said that taking samples, even inactivated, on a commercial flight, was a mistake. “We did that 20 years ago,” he says. “We don’t do that anymore.”doi: https://doi.org/10.1038/d41586-026-01995-7ReferencesMate, S. E. et al. N. Engl. J. Med. 373, 2448–2454 (2015).Google Scholar Koukouikila-Koussounda, F. et al. Nature Med. 32, 1666–1670 (2026).Google Scholar Adney, D. R. et al. Emerg. Infec. Dis. 20, 1999—2005 (2014).Google Scholar Fischer, J. F. et al. Viruses 14, 2227 (2022).Google Scholar Download references ‘Anxiety is palpable’: detention of researchers at US border spurs travel worries Mpox vaccine roll-out begins in Africa: what will success look like? Growing mpox outbreak prompts WHO to declare global health emergency Ebola outbreak: the data that show why researchers are so alarmedSubjectsVirologyGovernmentPoliticsInfectionLatest on:VirologyGovernmentPolitics