Gardaí in Killarney, Co Kerry, are investigating an alleged sexual assault on a 16-year-old male hotel worker last week which led to the arrest of a Fianna Fáil councillor.
The councillor, who is not from Kerry, was a delegate at a conference at a hotel in the town when the incident is alleged to have occurred.
He wrote to the party yesterday informing it that he has agreed to resign his membership and the party whip at both county council and town council level.
A Fianna Fáil spokesman said this was "pending the completion of the process and without prejudice to his position".
The assault is alleged to have occurred on September 26th. It is understood the teenager, a foreign national, was working with an agency employed by the hotel to cover busy periods.
At about 11pm, the councillor is alleged to have asked him for directions to his room and the young man accompanied him to show him the way, at which point the incident is alleged to have occurred.
The teenager immediately complained to the hotel's assistant manager and the hotel acted at once, with staff accompanying him to the local Garda station.
He returned to the station the following morning to make a formal complaint.
The councillor was subsequently arrested and questioned for a number of hours. He denied the accusation and was released without charge. A file is being prepared for the Director of Public Prosecutions.
The councillor was not available to comment when contacted yesterday.
However, in a statement on his behalf, the councillor's Killarney-based solicitor, Patrick O'Connor, said he had denied the allegations during questioning by gardaí, and continues to do so.