A watchdog group filed a complaint Monday with the Federal Election Commission saying that Interior Secretary Ryan Zinke used his dormant congressional campaign committee to benefit family and friends.

Zinke’s campaign bought an RV from his wife and sold it at a discount a year later to a friend in the Montana legislature, the Campaign Legal Center said in asking the FEC to probe the transaction. The campaign bought the RV from Lolita Zinke for $59,100 in April 2016 and sold it to his friend, Ed Buttrey, for $25,000 in June.

The FEC prohibits political committees from selling assets below fair market value.

Zinke was a U.S. congressman from Montana before assuming becoming interior secretary in March.

The Campaign Legal Center also asks the FEC to look into hotel stays in the Virgin Islands and New York that Zinke’s campaign paid for after he was nominated to serve in President Trump’s Cabinet.

The group says Zinke may have used a joint fundraising committee to permit donors to provide money to his campaign above federal contribution limits.

Zinke is already facing an investigation by the Interior Department’s inspector general’s office over his use of taxpayer-funded charter planes.

The U.S. Office of Special Counsel, meanwhile, is investigating whether Zinke broke the law when he gave a speech in June to a professional hockey team owned by a political donor.

In addition, members of Congress have asked for investigations into how Puerto Rico’s power authority secured a contract with a small firm from Zinke’s hometown to complete repairs after Hurricane Maria.

The Puerto Rico Electric Power Authority canceled the $300 million contract with Whitefish Energy on Sunday after criticism mounted.

Zinke said he had no involvement in the contract award and invited his department’s inspector general to investigate.

A spokeswoman for the Interior Department’s inspector general’s office told the Washington Examiner on Monday that it will not be investigating the contract because it “falls under the jurisdiction” of the Department of Homeland Security's inspector general.

The DHS inspector general’s office is still deciding whether to probe the contract, a spokesman told the Washington Examiner Monday.

“In light of PREPA's announcement to cancel the contract with Whitefish, our office is evaluating whether there are any remaining concerns that would benefit from review by an independent fact-finder,” the spokesman said.

However, the FBI has opened an investigation into the contract.