Rep. Eric Swalwell, D-Calif., an embattled lawmaker facing a potential expulsion threat, is the target of an investigation by the House Ethics Committee, the panel announced Monday.

At least four women have accused the California Democrat of sexual misconduct, according to multiple reports. The House panel said it is investigating an allegation "that he may have engaged in sexual misconduct toward an employee working under his supervision."

Swalwell suspended his gubernatorial campaign Sunday night amid widespread backlash following the sexual misconduct allegations.

Rep. Anna Paulina Luna, R-Fla., has vowed to introduce a resolution this week expelling Swalwell if he does not resign. Some Democrats have said they will support the measure. 

A spokesperson for Swalwell did not immediately respond to a request for comment.