The Independent Monitoring Commission is to meet the family of murdered Dublin man Joseph Rafferty, who was shot dead in west Dublin in April by an alleged IRA gunman.
The commission will discuss claims by his family that the murder amounted to a break in the IRA ceasefire.
The meeting, which is likely to add to growing political pressure on Sinn Féin regarding Mr Rafferty's murder, takes place in the next fortnight.
The IMC contacted Mr Rafferty's family just over a week ago and requested a meeting.
The commission's approach to the family comes after two months of intensive political lobbying by Mr Rafferty's sister Esther Uzell and her brother-in-law, Bart Little.
The family have begun a Justice for Joe campaign modelled on the campaign by the McCartney sisters in Belfast.
Ms Uzell last night told The Irish Times that she was not sure who from the IMC she and her family would be meeting but she believed they would be senior officials. "They rang us last Thursday week. They want to talk to us about the whole story basically. We'll tell them what happened from start to finish and we'll see what comes out of it."
A spokeswoman for the IMC said the commission could not comment. It had a policy of not disclosing the identities of those it meets or the nature of its meetings.
Ms Uzell and Mr Little last month had a meeting with the Taoiseach Bertie Ahern, who has told them he will raise the issue with the Sinn Féin president Gerry Adams during their next meeting.
The family has also met the main Opposition leaders here, all of whom have added their support to the campaign. They have held talks in Belfast with the sisters of Robert McCartney, who was murdered by members of the IRA outside a Belfast pub in January.
Mr Rafferty's family believe that, as well as being a member of the IRA, the murderer has actively campaigned for Sinn Féin candidates during elections in recent years.
The family want Sinn Féin and the IRA to actively encourage the murderer to give himself up.
The dead man, a 29-year-old father of one, was gunned down last April in the Ongar housing estate in west Dublin where he lived. He was originally from the south inner city; in the months leading up to his murder he had become embroiled in a dispute with a family from that area.
Mr Rafferty was told a number of times by members of the family he had clashed with that he would be "got" by the IRA.
The woman whose sons he had become embroiled with is in a relationship with a former member of the IRA. He is the only suspect in the murder.
Ms Uzell reported the threats against her brother's life to Cllr Daithí Doolan of Sinn Féin late last year and early this year.
Mr Doolan has said at no time was any threat to Mr Rafferty's life reported to him. He has condemned the murder.