The personal information of more than 40,000 federal workers may be at risk following a data breach at KeyPoint Government Solutions, a prominent federal contractor.

Employees were notified that their information may be at risk by the Office of Personnel Management (OPM), which confirmed the breach on Thursday, according to an Associated Press report.

A spokesperson for the OPM said that following an investigation into the breach, the agency found that “no sensitive information was removed from the system.” Those impacted will be offered free credit monitoring.

This marks the second data breach this year that has had an impact on a major organization that performs background checks on employees at federal agencies.  

In August, the U.S. Investigations Services became the victim of a data breach which impacted up to 25,000 government workers. That attack was believed to be state-sponsored.