The Chinese researcher who was on his way to Beijing when a customs officer pulled him aside and searched his luggage, finding 21 vials of “biological material” in a sock in his suitcase, likely coordinated with the Chinese government, according to prosecutors.

At a hearing Monday in Boston, Magistrate Judge David Hennessy granted a request to hold Zaosong Zheng, 29, without bail.

Zheng’s case is part of a federal investigation into hundreds of cases involving the potential theft of intellectual property by Chinese nationals. His case “was not an isolated incident,” prosecutors stated in the motion to hold him without bail.

“Rather, it appears to have been a coordinated crime, with likely involvement by the Chinese government,” they said.

Authorities alleged Zheng stole vials of cancer cells from a laboratory at Beth Israel Deaconess Medical Center. Two other Chinese scientists who worked at the same laboratory as Zheng had successfully smuggled stolen biological material out of the country, prosecutors said in court documents.

Zheng was preparing to board Hainan Airlines Flight 482 from Boston to Beijing in early December when customs officers identified the Chinese national as “a high risk for possibly exporting undeclared biological material,” according to the affidavit.

Under questioning, Zheng first said the vials “were not important and had nothing to do with his research.” Then he admitted he had stolen eight samples and had replicated another 11 based on a colleague’s research. On his return to China, he planned to take the samples to Sun Yat-sen Memorial Hospital and publish the research under his own name.

Zheng booked another flight to China for the next day and was detained by the FBI at the airport when he arrived. He waived his Miranda rights through a Mandarin interpreter and told the agents he planned to use the material for cancer research. He was then arrested.

Zheng’s former roommate told investigators, according to court documents, that the researcher had packed all his belongings ahead of his flight, indicating that Zheng did not plan to return to the United States.

He was in the U.S. on a visa sponsored by Harvard University, which has since been revoked, a spokesman for the University told the New York Times.