BOSTON • Chinese scientist Zheng Zaosong was preparing to board his flight from Boston to Beijing when Customs officers pulled him aside.

Inside Zheng's checked luggage, wrapped in a plastic bag and then inserted into a sock, officers found 21 vials of brown liquid that contained cancer cells.

Zheng, 29, a cancer researcher, had taken these from a laboratory at Beth Israel Deaconess Medical Centre. Court documents noted that he admitted taking eight of the samples and had replicated 11 more, based on a colleague's research.

When he returned to China, he said, he would take the samples to Sun Yat Sen Memorial Hospital and publish the results in China, under his own name.

Zheng's arrest signified an escalation in the Federal Bureau of Investigation's (FBI) efforts to root out scientists who, the authorities say, are stealing research from American laboratories. Federal prosecutors warn that he may be charged with transporting stolen goods or with the theft of trade secrets, a felony that brings a jail term of up to 10 years.

On Monday, Magistrate Judge David Hennessy granted prosecutors' wish to hold Zheng without bail, noting that the theft appeared to have the support of the Chinese government. Two other Chinese scientists who worked in the same lab had successfully smuggled stolen biological material out of the country, prosecutors say.

Zheng's case is the first to unfold in the laboratories clustered around Harvard University.

Federal officials are investigating hundreds of cases involving the potential theft of intellectual property by visiting scientists, nearly all of them Chinese nationals.

FBI director Christopher Wray described the researchers as "non-traditional collectors" of intelligence who were part of a collective effort to "steal their way up the economic ladder at our expense".

NYTIMES