Hackers sponsored by the Chinese military are being blamed in a new U.S. government hacking case, according to a report.

Citing people with knowledge of the breach, Reuters Friday said the Federal Deposit Insurance Corp. was hacked for several years beginning in 2010. The Federal Bureau of Investigation is said to be investigating the security breach, which saw hackers gain access to dozens of computers at the FDIC including the workstation of former Chairwoman Sheila Bair.

Established in 1933, the FDIC is a government corporation providing deposit insurance to depositors in U.S. banks. Along with having access to million of individual deposits, it also oversees plans for how big banks would handle a financial crisis and possible bankruptcy.

The FDIC reported no fewer than seven cyber security incidents deemed “major” between 2015 and 2016, with an annual report stating there were 159 incidents of unauthorized computer access during fiscal year 2015.

“We are continuing to take steps to enhance our cybersecurity program,” FDIC spokeswoman Barbara Hagenbaugh said in a statement. For example, the bank regulator no longer allows thumb drives, and is said to be coordinating more closely with the Department of Homeland Security to keep such breaches from happening in the future.

Placing the blame on China could be somewhat premature, as Reuters noted that its anonymous sources were unable to provide any solid information supporting the claim. According to two people cited in the story who took part in the review, the FDIC last month “allowed congressional staff to view internal communications between senior FDIC officials” related to the hacking. “In the exchanges, the officials referred to the attacks as having been carried out by Chinese military-sponsored hackers, they said. The staff was not allowed to keep copies of the exchanges, which did not explain why the FDIC officials believe the Chinese military was behind the breach.”

The Chinese government neither confirmed nor denied involvement in the FDIC hack. Chinese Foreign Ministry spokeswoman Hua Chunying said only, “If you have no definitive proof, then it is very hard for you to judge where the attacks really come from.”

Image credit: 22711505@N05/Flickr/CC by 2.0