WASHINGTON (Reuters) — The top Republican in the U.S. House of Representatives on Wednesday resisted calls to punish a staunch ally of President Donald Trump who, according to a U.S. law enforcement source, faces a federal probe into a relationship with an underage girl.

Republican Leader Kevin McCarthy said he would not strip Representative Matt Gaetz of his committee assignments absent proof that he has engaged in wrongdoing, as Democrats have demanded.

Gaetz is being investigated by the U.S. Justice Department for possibly violating sex-trafficking laws by paying travel expenses for a 17-year-old girl with whom he was romantically involved, according to a U.S. enforcement source who spoke on condition of anonymity. Gaetz has denied wrongdoing.

The story was first reported in the New York Times.

“Those are serious implications. If it comes out to be true, yes, we would remove him, if that was the case. But right now, Matt Gaetz says that it’s not true and we don’t have any information. So let’s get all the information,” McCarthy said on Fox News.

He said he expected to speak to Gaetz later on Wednesday.

Gaetz, an outspoken 38-year-old conservative who has cast himself as an avid leader in Trump’s America First movement, has denied the allegations and said in a statement that he and his family are the victims of an “organized crime extortion.”

Democrats called on McCarthy to strip Gaetz of his committee assignments while the federal probe is underway, especially his seat on the House Judiciary Committee, which oversees the Justice Department. Gaetz also sits on the House Armed Services Committee.

Reporting by David Morgan and Mark Hosenball Editing by Andy Sullivan and Howard Goller