Sinn Féin is rejecting claims that IRA figures involved in the murder of two RUC officers in 1989 have withdrawn co-operation with the tribunal investigating the killings.

The Smithwick Tribunal was told that the men were not prepared to give oral evidence to the hearing, despite a promise that their identities would be protected.

Judge Smithwick is examining claims that gardaí gave information to the IRA prior to the ambush and murder of RUC Chief Superintendent Harry Breen and Superintendent Bob Buchanan.

Taoiseach: Those involved should give evidence

The Taoiseach says former paramilitaries should do the decent thing and engage with the Tribunal.

The inquiry has broken off contact after they refused to give oral evidence.

Enda Kenny says the former provisionals should do the right thing.

"Those who were engaged in the Smithwick Tribunal should now have the decency to give of the information that is necessary for the Smithwick Tribunal to do it's work" he said.

But Mary-Lou McDonald of Sinn Féin says the individuals involved have already provided extensive information.