Virginia Gov. Terry McAuliffe is a subject of a federal investigation looking at donations to his gubernatorial campaign, according to a U.S. law enforcement official.

The official spoke on condition of anonymity because he was not authorized to speak publicly about an ongoing investigation. CNN first reported the story Monday.

Marc Elias, a lawyer for McAuliffe’s campaign, said Monday that the governor, a Democrat, is unaware of any investigation.

“The Governor will certainly cooperate with the government if he is contacted about it,” Elias said in a statement.

Spokespeople at the FBI and Justice Department declined comment Monday.

The law enforcement official did not say what specific contributions were drawing scrutiny, but said that campaign finances and donations to his 2013 campaign were part of the investigation.

The official said the investigation has been ongoing for some time and there was no indication that it was close to concluding.

McAuliffe’s predecessor in the governor’s mansion, Republican Bob McDonnell, was convicted on federal corruption charges but has appealed his conviction to the U.S. Supreme Court.

Before winning his gubernatorial campaign in 2013 over Republican Ken Cuccinelli, McAuliffe made his name in national Democratic politics as a prolific, well-connected fundraiser with close ties to Bill and Hillary Clinton.

Although McAuliffe is close to the Clintons, the official told AP that the investigation of McAuliffe is unconnected to a separate FBI investigation looking at the legality of private email servers that Hillary Clinton used while serving as secretary of state.

Last year, McAuliffe’s political action committee, Common Good Va., returned a $25,000 donation from a company with ties to Angola’s state-owned oil company after The Associated Press raised questions about its legality. Federal law prohibits campaigns at any level from receiving money from outside the U.S.

McAuliffe’s international business connections also came under scrutiny prior to his gubernatorial campaign. He served as chairman of GreenTech Automotive, a company that hoped to bring supercompact automobiles to the U.S. market. The company attracted hundreds of thousands of dollars in foreign investment, in part through a federal program that granted visas to investors who met certain job-creation thresholds.

McAuliffe resigned from the company in December 2012. GreenTech, which received millions of dollars in economic incentives from state and local officials to build a plant in Mississippi, faced criticism for falling well below expectations in production and job creation.