MICHEAL Martin has claimed that he is in possession of documents that allege a series of murders, abductions and serious assaults that were not properly investigated.
The Fianna Fáil leader said he has sent the documentation containing the allegations to Taoiseach Enda Kenny.
At a press conference today, Mr Martin said the allegations are so serious that an independent investigation is now required.
He said he has today examined documents relating to ten cases which involve "abduction, assault and ultimately murder".
The documents were provided to him by a garda whistleblower, Mr Martin claimed this afternoon.
"I have sent material to the Taoiseach in relation to other issues the whistleblower has raised, pertaining to issues outside of the penalty points dossier, which relate to the failure to fulfil basic functions in terms of a range of cases, very very serious cases, - involving abduction, assault and ultimately murder - which leaves huge questions for response," he told reporters.
Mr Martin said Mr Kenny must not simply refer the documentation to the Department of Justice.
"I'd say to the Taoiseach that they're not something that should just be referred back to Justice again,because we've been around that circle far too often now with absolutely no clarity emanating or any real fundamental response taking place. I think we're heading towards an independent investigation into all of this that has to be at arms length from the minister of justice and the department of justice."
Mr Martin said he held a meeting in Portlaoise last week with garda whistleblower Sgt Maurice McCabe. He said Justice Minister Alan Shatter must correct the Dail record and acknowledge that Sgt McCabe attempted to cooperate with an investigation into penalty points controversy.
Mr Martin said he does not believe Mr Shatter's position is tenable, but stopped short of calling on him to resign.
A spokesperson for Mr Shatter said no response will be made at this particular time.
By Niall O'Connor, Political Correspondent