Xinhua, China's official news agency, said an investigation into the OPM breach last year determined it was not state-sponsored.
The news agency did not give details of who conducted the investigation, or whether U.S. officials agree with the conclusion.
U.S. and Chinese officials have been meeting in Washington this week for the first round of cybersecurity talks following the signing of a bilateral anti-hacking accord in September.
U.S. officials had privately linked the OPM breach to Chinese hackers. The story by Xinhua is the first to officially link the two.
The talks taking place this week mark an ongoing effort to repair relations after China withdrew from a working group last year, when the U.S. Department of Justice indicted Chinese military hackers for cyberespionage against U.S. companies in the nuclear power, metals and solar products industries.
Xinhua reported that during the talks, China and the U.S. reached a broad agreement on the joint fight against cybercrimes. The next meeting is scheduled for June 2016, Xinhua said.