The Kerry Sinn Féin TD, Mr Martin Ferris, has called for an independent Garda complaints body following the rejection of his complaint that he was assaulted last March at Killarney Garda station.
The Garda Complaints Board said yesterday that it had rejected the complaint, while the DPP found no evidence to support a criminal charge against any gardaí.
A complaint of Garda harassment made by Mr Ferris's director of elections, Mr James Sheehan, has also been rejected.
Mr Ferris said he was now taking legal advice as to whether he should take a civil action against individual gardaí.
Mr Ferris was arrested last March by gardaí investigating the abduction of a man near his home in Castleisland, Co Kerry, three months previously.
He was held at Killarney Garda station for 12 hours, during which, he says, a garda assaulted him. He was released without charge.
He made an official complaint, which he says was supported by medical and photographic evidence. However, the Garda Complaints Board has now rejected the complaint.
Mr Ferris said yesterday the DPP's decision and the statement from the Garda Complaints Board that "the matter was now closed" reinforced his view that there needs to be "an independent complaints body or ombudsman established to deal with complaints against members of the Force".
He said it was "a joke that we still today have a situation where gardaí are investigating themselves. With all the statements coming from the Morris Inquiry indicating widespread Garda corruption it is imperative that public confidence is restored in the force."
In July Tralee District Court dismissed a charge against Mr Ferris that he had used threatening and abusive behaviour towards a Garda sergeant in a separate incident.