Martin made the claims as he defended the garda whistleblower Maurice McCabe who he said was owed an apology from the Minister for Justice Alan Shatter as he is a”a credible person”.

Martin said that he has sent material to Enda Kenny “in relation to other issues that the whistleblower has raised” saying the material “relates to the failure to fulfil basic functions in terms of a range of cases, very serious cases involving abduction, assault and ultimately murder”.

The material was given to him by McCabe and concerns some cases which have been in the public domain. He cited one of these as the murder of Sylvia Roche Kelly who was found dead in the Clarion Hotel in Limerick in December 2007.

The Garda Ombudsman is investigating claims of an alleged cover-up of charges against the man convicted of the murder, Jerry McGrath, who was found guilty in March 2008.

‘It will go into the sand’

Martin did not say how McCabe got the information, but said that it should not be passed to the Department of Justice where “it will go into the sand”. Instead, he called for it to be dealt with by the Taoiseach by setting up a Commission of Inquiry “which is independent, with full powers”.

He said the files he has handed over detail the circumstances around assaults and murders and how they were dealt with and the consequences for the victims over a number of years, but was not specific.

The TD added that he believes Shatter’s position is not tenable, but he did not immediately call for him to resign.

“I believe his position is not tenable but that’s not my immediate focus, my immediate focus is the administration of justice and getting these issues sorted,” he said.

He said that Shatter should correct the public record and acknowledge that McCabe attempted to cooperate with an internal investigation into the penalty points controversy by gardaí as well as apologise to the garda sergeant himself.

Martin said he met McCabe for three hours in Portlaoise last Friday.

Earlier: Alan Shatter has sacked the garda confidential recipient Oliver Connolly

Dáil: ‘Can I suggest you relieve Minister Shatter of his duties?’ Mary Lou McDonald’s advice to Enda Kenny this afternoon