Democratic Rep. Katie Hill has admitted to having an “inappropriate” relationship with a campaign staffer, according to multiple reports.

On Wednesday night, the California congresswoman reportedly sent a letter to her constituents, admitting that she had engaged in an improper relationship with a campaign aide before entering Congress, according to CNN. Her confession came just hours after the House Committee on Ethics announced it was opening an investigation into Hill over allegations that she was romantically involved with a congressional staffer.