ACT leader Rodney Hide says he has reprimanded MP David Garrett, for making a lewd remark to a female staff member.
Mr Hide says it was not a formal warning, but he has made it clear he expects a higher standard of behaviour from members of his party.
He says a male staff member approached him after hearing Mr Garrett make the inappropriate remark to a female staffer.
When Mr Garrett was approached, he apologised to Mr Hide and the staff member concerned.
Mr Garrett says he regrets making the comment, and has been on a steep learning curve since entering Parliament.
ACT president Michael Crozier says he expects the party's board will receive a report in due course.