Sinn Féin’s Justice Spokesperson has said that the party will work constructively with Drew Harris, the newly appointed Garda Commissioner.
Mr Harris's appointment as Garda Commissioner is set for a five-year period.
Speaking on RTÉ's Morning Ireland, Donnchadh Ó Laoghaire said Sinn Féin had worked with Mr Harris during his time in the PSNI and that it would continue to hold him to account, as it had with previous commissioners.
He said comments made by Mr Harris to the Smithwick Tribunal, that garda officers had colluded in the murders of two RUC officers, were very serious, and that allegations of collusion - north and south - needed to be pursued.
The Smithwick Tribunal was set up to investigate claims that a garda passed information to the IRA, which led to the ambush and deaths of two senior RUC officers in March 1989.
Chief Superintendent Harry Breen and Superintendent Bob Buchanan died just minutes after leaving a meeting in Dundalk Garda Station.
Mr Ó Laoghaire said policing reform was a central part of Sinn Féin's negotiations and the PSNI was subject to strict accountability and restrictions.
He also said he did not believe the Government had done enough to properly pursue the Dublin-Monaghan bombings, and that it must now follow up with the British government.
Paramilitaries detonated four no-warning bombs in Dublin and Monaghan on 17 May 1974, killing 33 people.
Mr Ó Laoghaire's comments come as a survivor of the Miami Showband massacre described Mr Harris's as a "massive step backwards".
Stephen Travers said it was a "hammer blow" to every victim of collusion between British security forces and loyalist terrorists, and described it as "putting the fox in charge of the hen house".
Mr Travers and Des McAlea were injured when they and the three other members of the popular band were taken from their tour bus and shot on a country road after a gig in Banbridge, Co Down in July 1975.
Lead singer Fran O'Toole, guitarist Tony Geraghty and trumpeter Brian McCoy were killed in the massacre.
Speaking on the same programme, Mr Travers said that he was part of a civil action against the Chief Constable of the PSNI and the British Ministry of Defence.
He said the office of the chief constable, of which Mr Harris is currently the second most senior officer, has blocked, delayed and frustrated every effort to access the files on those responsible for the atrocity.
Mr Travers said that Mr Harris can swear allegiance to uphold the Irish Constitution as many times as he likes, but he would prefer if he just held up his hand and said he would no longer block the files on the Miami Showband massacre and the Dublin-Monaghan bombings.
Being a victim, he said, does not qualify Mr Harris to take over the garda role.
The newly appointed commissioner's father, Alwyn Harris, an RUC officer, was killed in an IRA car bomb in 1989.
Harris to bring in support staff
Minister for Justice Charlie Flanagan has said there may be an opportunity for Mr Harris to bring a small number of support staff with him when he assumes the position in September.
However, the minister said the commissioner will be working garda management.
The Minister for Finance has said that Mr Harris's appointment was a sign of the change taking place in Ireland.
Paschal Donohoe said that the signal being sent out by his appointment as Garda Commissioner was a positive one.
He added that Government would continue to pursue matters in relation to the Dublin-Monaghan bombings.
The General Secretary of the Association of Garda Sergeants and Inspectors (AGSI) has said that the association was delighted that the position of Garda Commissioner has been filled.
Speaking on RTÉ's Today with Sean O'Rourke, John Jacob said the association was looking forward to working with Mr Harris.
He said that the new commissioner needed to be given an opportunity to "get his feet under the table", assess the major issues and meet senior management to outline his plans.
When asked about the comments made by Mr Harris to the Smithwick Tribunal, Mr Jacob said the organisation needed to look forward and not to look for problems in the past.
The AGSI has, he said, always cooperated with change.