The New York Times reported that security investigators traced the hacking to computers at Shanghai Jiaotong University and Lanxiang Vocational School in China.
The official Xinhua News Agency cited an unnamed university spokesperson Saturday as saying the allegation against it is baseless, and an official at the vocational school said its investigation found no evidence the attacks originated there.
Li Zixiang, a Communist party official in the Lanxiang school in the eastern Shandong province, said students there are currently on their winter break. He also disputed the Times report that some evidence linked attacks to one computer science class taught by a Ukrainian. "We have never employed any foreign staff," Xinhua quoted Li as saying.
Another official at the vocational school disputed the Times' report that Lanxiang had close ties to the military.
Zhou Hui, director of the school's general office, told Xinhua that some students had joined the military after school, but it was natural for citizens to do so.
Google revealed Jan. 12 that digital thieves had stolen some of its computer code and tried to break into the accounts of human rights activists opposed to China's policies. The sophisticated theft also targeted the computers of more than 30 other companies, according to security experts
The digital assault was serious enough to prompt Google to confront China's government about censorship rules that weed out politically and culturally sensitive topics from search results in the country. Google says it's prepared to shut down its China-based search engine and the company and the government are still discussing a possible compromise.
China has denied involvement in Internet attacks and said in January its anti-hacking policy is transparent and consistent.