Scientific knowledge may be universal but scientists can suffer discrimination and persecution like everyone else. Recent reports of Chinese researchers in the United States being accused of smuggling biological materials suggest carelessness on the part of the researchers or, more likely, deliberate scapegoating by US law enforcement agencies. They appear to fit an enduring pattern of official harassment against Chinese scientists under the guise of combating industrial espionage and intellectual property theft.

The cases involved several scientists previously associated with the University of Michigan, a leading US research university. They were arrested publicly, detained and deported – in other words, they were treated like criminals or bioterrorists.

In the case of the three researchers charged last November, top Federal Bureau of Investigation and Justice Department officials accused them of trying “to advance a malicious agenda” by smuggling biological samples. The specimen turned out to be mostly harmless, tiny, transparent worms. A court subsequently dismissed their cases.

Not everyone was so lucky. Wang Danhao, a fellow university researcher and a promising talent in the field of semiconductors, died from a fall in March after being questioned by federal agents. In a letter to this newspaper, the California Scholars for Academic Freedom criticised the university for “its lack of support for its Chinese scholars in the face of heavy-handed tactics employed by federal authorities”, adding that they were “especially disturbed by the silence of the University of Michigan administration”.

The university is, of course, not the only one. In the past decade, similarly spurious cases – some resulting in guilty pleas under heavy prosecutorial pressure – have created an atmosphere of fear and persecution at universities and research institutions across the US. Those targeted could not expect much support from their employers. As a result, there has been an exodus of Chinese scientists and engineers back to China, including renowned biologist Xu Xianzhong, previously a professor at the University of Michigan.

It should be clear by now that Chinese researchers are no more likely to commit academic fraud or crimes than their other ethnic peers in the US. The US has been able to maintain its post-war pre-eminence in science and technology because it could attract talent from all over the world. It needs to guarantee equal legal protection for the legitimate rights of researchers regardless of nationality if the US is not to lose its attractiveness as a science powerhouse. China, though, is more than happy to welcome them with open arms.