The online attacks that hit Google and a number of other organisations in January have been traced back to two schools in China, according to reports.
The attacks could have begun months before they came to light, and would have been used to siphon off trade secrets and access the Gmail accounts of human rights activists.
Two institutions are thought to have owned computers used in the attacks, the Shanghai Jiapong University and the Lanxiant Vocational School, one of which is apparently tied to the Chinese military.
Google hinted last week that it may take years to resolve its issues with the Chinese government. The company said in January that it will no longer censor search results on google.cn, and has already postponed an Android phone launch in the country.
The spat reached the highest levels in the US when secretary of state Hillary Clinton demanded an explanation from the Chinese government.
Google handed over the details of the intrusion to the National Security Agency earlier this month in an effort to identify the culprits.
The latest revelations suggest that this is perhaps having some effect.