The House ethics committee said on Wednesday that it has opened an investigation of Tony Gonzales, a Republican representative from Texas, over allegations that include having an affair with an aide.

The top Republican and Democratic members on the committee said in a joint statement that an investigative panel would look into whether Gonzales engaged in sexual misconduct toward an employee in his office and whether he discriminated unfairly by dispensing special favors or privileges.

Gonzales’s office did not immediately reply to a request for comment from the Associated Press.

The congressman, now in his third term, has said he would not step down in response to the allegations, telling reporters at the US Capitol recently that there will be opportunities for all the details and facts to come out.