John Conyer Jr. will sue the House Ethics Committee for $10 million to cover his legal fees after the panel announced on Wednesday that he had violated ethics rules by asking a former staffer to pose for a photo with him at a dinner.
The committee said the incident occurred in late March and Conyers, a Michigan Democrat, is seeking to recoup money he paid to his accuser.
Conyers is the longest-serving member of the House and the first black member to be elected to the House in 20 years.
The allegations of misconduct against Conyers came to light when a woman told the Washington Post she had made unwanted sexual advances towards Conyers.
The woman, who was not identified, told the newspaper she did not recall whether Conyers ever asked her for a date but did say she did recall being “shocked and embarrassed” when Conyers “turned his back on me.”
She said she had not spoken to Conyers since then and that the incident had not happened in a public setting.
In the statement announcing the lawsuit, Conyers’ attorney, Brian Wiegert, said Conyers did not “engage in any improper conduct.”
The ethics committee did not immediately respond to a request for comment.
The Associated Press contributed to this report.