A U.S. congressional ethics panel opened an investigation Tuesday into Republican Representative Max Miller after he requested the probe, saying he wanted to clear his name following abuse allegations made by his ex-wife.

Miller, who has denied the allegations, is seeking reelection in Ohio’s 7th Congressional District. If he drops out of the race, Republicans would have to select a new candidate under state law by August 10.

President Donald Trump weighed in on the matter Monday, calling it a sad situation and saying it was something the families would need to resolve.

On Sunday, U.S. Senator Bernie Moreno, a fellow Ohio Republican, called Miller “a danger” to his ex-wife, who is also Moreno’s daughter, and said Miller should not serve in Congress. Emily Moreno and Miller were married until last year.

Miller and Moreno both owe their political rise to close associations with Trump. The allegations against Miller, who has said he will remain in his congressional race, threaten to put what had been a safe Republican seat in play for Democrats in this November’s midterm elections.

“The Committee … is reviewing allegations that Representative Max Miller may have engaged in domestic violence and abuse or illegal drug use in violation of the Code of Official Conduct or any other applicable standard of conduct,” the panel said in a statement.

Earlier, Miller had said he would file paperwork for an ethics investigation to clear his name.

Emily Moreno has alleged that Miller burned her with boiling hot water and physically abused her and their toddler daughter. Miller has disputed his ex-wife’s allegations in a video recording.

“I have absolutely nothing to hide,” Miller said in an X post. He said he would provide the committee with all necessary documents for an examination.

Moreno previously said he would “not litigate these matters in the media” and that he would prioritize the safety and well-being of his daughter and granddaughter. While the senator hoped to keep the matter private, Miller’s “increasingly erratic and dangerous behavior has made that impossible,” Moreno wrote on Sunday.

Trump, asked about the issue on Monday, said of his former aide: “It’s a very sad thing. I know Max; he’s a good person. I mean, I always thought he was a very good person, and I’m going to let the families figure that out.”

Miller was a senior White House aide during Trump’s first administration.

Democrats only need to flip a handful of seats to regain control of the House of Representatives, where Republicans currently hold a 218 to 214 edge, with three seats vacant.