By Dustin Volz

WASHINGTON (Reuters) - The U.S. House of Representatives has subpoenaed the U.S. Office of Personnel Management for documents related to the hacking of the agency’s files that compromised sensitive information of roughly 22 million people, Representative Jason Chaffetz said on Wednesday.

Chaffetz, a Utah Republican who heads the House’s oversight panel, said that Office of Personnel Management acting director Beth Cobert was not cooperating with his committee’s investigation by failing to produce unredacted versions of network security guides that were stolen in the data breach.

“Ms. Cobert is not working in good faith with the committee,” Chaffetz said. “I will use all available remedies to obtain the information needed to conduct a thorough and meaningful investigation.”

An Office of Personnel Management spokesman, when asked about the subpoena, pointed to written testimony given by the agency last month stating it "has made every effort to work in good faith to respond to multiple congressional oversight requests, including document productions."

The files, which Chaffetz has requested for several months, were “outdated security documents” seized during the hack, according to June 2015 testimony by Donna Seymour, the agency’s chief information officer.

The Office of Personnel Management has provided partially redacted versions of those manuals, which it has said contained sensitive information about its information technology.

Chaffetz has expressed concern that the manuals could be used to launch another cyber attack.

The intrusion, which began in 2014 and was disclosed publicly last year, exposed the names, addresses, Social Security numbers and other sensitive information for current and former federal employees and contractors, as well as applicants for federal jobs and individuals listed on background check forms.

U.S. officials have privately blamed China for the hacking. Beijing has denied the allegations, and China's state news agency has said the breach was carried out by a criminal enterprise.

Cobert is scheduled on Thursday to testify before a Senate panel considering her nomination to a four-year term as Office of Personnel Management chief.