Sinn Féin presidential candidate Martin McGuinness today denied knowing the identity of those responsible for the killing of a garda and Army private involved in the rescue of kidnapped businessman Don Tidey in 1983.

Canvassing in Athlone, Co Westmeath this afternoon, Mr McGuinness was confronted by the son of the late Private Patrick Kelly.

Pte Kelly (35) and Garda Gary Sheehan (23) were shot dead while trying to rescue Mr Tidey, who was being held by the Provisional IRA at Derrada Woods, Co Leitrim on December 16th, 1983.

Holding a picture of his father, David Kelly said: "I want justice for my father. I believe you know the names of the killers of my father and I want you to tell me who they are. You were on the army council of the IRA."

In response, Mr McGuinness denied any knowledge of the individuals involved. "I don't know their names," he said, before denying he was on the army council of the IRA.

Mr Kelly branded the presidential candidate “a liar” and vowed to wage a campaign against Sinn Féin until he found out who was behind his father’s killing.

“He was loyal to the Irish Republic and I’m loyal to him as a son, and I’m going to get justice for him,” he said.

“I want justice for my father and I want you to get your comrades who committed this crime to hand themselves into the gardaí,” said Mr Kelly.

“I don’t know who was responsible for the killing of your father but I fully and absolutely sympathise with you,” Mr McGuinness replied. “I have been at the heart of a very important peace process in the North over the last 20 years which has brought conflict and violence and death to an end and I am going to continue with that work because that’s the work of peace.

“This is in the past. You are heartbroken on account of it and my sympathy is 100 per cent with you and your family,” he added.

Speaking about the incident later in Trim, Co Meath, Mr McGuinness said that as someone who had lost friends and neighbours in "tragic and violent circumstances" he was "deeply conscious of the deep hurt and pain that has been caused as a result of the conflict".

“Last week as I set off on this presidential campaign, I spoke in Derry, a town that has suffered much hurt and saw many lives lost during the conflict," he said.

"I said that my heart went out to the families of all those who have been killed. Of course this also includes the families of those in this part of Ireland, including members of the Gardai and Defence Forces, who lost their lives."

Mr McGuinness said that as a republican leader he had "never and would never" stand over attacks on gardaí or the Defence Forces.

“For many years now I have dedicated myself to building and upholding a peace process which will consign violent conflict to history. That peace process is recognised as one of the most successful in the world. We are now in a far better place," Mr McGuinness said.

He said he understood that the individual pain felt by victims and the relatives of victims "on all sides and none in the recent conflict" could not be healed overnight.

"Some may never heal. I believe we need a real process of national reconciliation which deals with the pain and the hurt that has been caused but which also seeks to build a new, peaceful and reconciled Ireland.

"Building peace requires a continuous and ongoing effort to build relationships, to dialogue, to outreach, to go the extra mile for peace. Ireland as a Nation can only grow if we are at peace with ourselves as a people. That is a 32-county project. Peace building transcends partition. I want to deepen and expand the role of the President to lead the process of national reconciliation in Ireland."