An independent federal agency is looking into donations made earlier this year to acting Attorney General Matthew Whitaker's 2014 Senate campaign, according to a new report.

Such contributions might violate the Hatch Act, which limits the ways federal government employees can engage in political activity.

CNN reported that four contributors donated a total of $8,800 to Whitaker's Senate campaign committee in January and February, while Whitaker was chief of staff at the Department of Justice. The campaign committee still owes nearly $50,000 to Whitaker himself from his unsuccessful attempt at one of Iowa's Senate seats.

Nonprofit watchdog organization American Oversight announced Wednesday it had submitted complaints related to Whitaker's financial disclosure forms to the Office of Special Counsel, alleging potential violations of the Hatch Act and to the Office of Government Ethics and the Department of Justice’s Ethics Office, alleging a failure to disclose. The organization states the contributions were the first activity by Whitaker's campaign in several years.

A spokesperson for the Office of Special Counsel confirmed to CNN the office had received the complaint and said a case file has been opened. Neither the Justice Department nor Whitaker commented to the network.