An insecurity consultant whose work is available for use by the Chinese government wrote the code used to hack into Googlemail accounts in the Peope's Republic, according to a report in the Financial Times.
The FT quoted an unnamed investigator working for the US government.
Chinese authorities deny any role in cyber attacks conducted against Google and other US corporations' web sites that appeared to emanate from inside the country.
The author of the code hadn't conducted the attacks himself, but had posted the hack on a known hackers forum, the FT's source said.
He claimed the coder has to "toe the line now and again," to be able to carry on the work he's good at. "He would rather not have uniformed guys looking over his shoulder, but there is no way anyone of his skill level can get away from that kind of thing," the US source said. "The state has privileged access to these researchers' work."
The New York Times reported over the weekend that the attacks had been traced to computers at a Chinese university and a school claimed to have links to the Chinese military. A spokesman for Shanghai Jiaotong University said he was "shocked and indignant to hear these baseless allegations which may harm the university's reputation."
The Lanxiang Vocational School in eastern Shandong province, also denied the allegations. But as well as training hairdressers, car mechanics and chefs, the school also claims to have the "biggest" computer lab in the world.