The parents of Paul Quinn, who died in October 2007 after being severely beaten in a shed near Castleblayney in Co Monaghan, have travelled to Leinster House to campaign on behalf of their son.
Mr Quinn's mother, Breege Quinn, said she wanted Sinn Féin’s Finance Minister in Northern Ireland, Conor Murphy, "to say the simple words that Paul Quinn was not a criminal".
At the time of the murder, Mr Murphy alleged that Mr Quinn was involved in criminality before he was killed.
Mr Murphy said in 2007 that he had spoken to IRA men in Cullyhanna, Co Armagh who reassured him that the murder was not carried out by the IRA.
She said she also wanted him to go to the PSNI and the gardaí and give the names of the Provisional IRA members he met in Cullyhanna about the case.
Ms Quinn said she was not satisfied with what she termed "obscure apologies" to date, and alleged that "the slur' that her son had been a criminal is being 'actively promoted by Sinn Féin.'
She said Mr Murphy's refusal to do what the Quinn family asked raised a question: 'Who's the leader of Sinn Féin now - is it Mary Lou McDonald or is it the IRA? Because it seems that Mary Lou has no say in telling Conor Murphy to come out and give the Quinn family justice for the murder of their son."
Ms Quinn said her family would not meet Sinn Féin representatives until "Conor Murphy came to the media, on national television, and say to us that Paul Quinn is not a criminal".
Last month, Mr Murphy told RTÉ News: "Remarks that I made at the time of his killing are a matter of regret. I am sorry that that has added to the grief that the family has felt. I want to apologise to them for that. I want to withdraw those remarks."
Mr Murphy added: "I have consistently condemned the killing of Paul Quinn. I have said that those responsible for this murder are criminals and deserve to be brought to justice."
Ms McDonald has also spoken to the Quinn family on the phone.
"He (Conor) has made an apology. It's sincerely made and I hope and trust that the Quinn family will get some level of comfort from that," Ms McDonald said last month.
"But ultimately the issue here is that those who carried out the murder are actually brought to justice."