The campaigning McCartney sisters of Belfast, who have been pressing for justice for their murdered brother Robert, were warned by police last night of threats against them.
The five sisters, who have been locked in a battle with republicans since their brother was stabbed to death outside a Belfast bar in January, said police had told them of a threat to burn their homes.
The sisters said police told them the threat had come from "criminal elements". There was no immediate clarification whether this meant republicans or others unconnected with Sinn Fein and the IRA.
The threat also extended to Robert's fiancée, Bridgeen Hagans, and to a sandwich bar run by one of the sisters, Donna.
While the Police Service of Northern Ireland would not comment on the development last night, the fact that officers visited the McCartney family is taken as evidence that detectives regard the threat as serious.
The family has for months been a major embarrassment to the republican movement, which has nonetheless offered the sisters public support.
One of the sisters, Catherine McCartney, said she believed the threat had come from within republicanism. She added: "For the past three months we have been asking the movement to stop protecting the criminals who murdered Robert that night.
"And now today after our campaign, we get a threat saying our houses are going to be burned down. I'm not frightened for myself personally but I have four children here, from 13-years-old down, so I have to take it seriously for them."
Robert McCartney was stabbed outside a Belfast city centre bar after a fracas inside the pub. Police believe three IRA members were involved in the incident but although the three have been questioned by detectives they remained largely silent in interview.
The McCartney sisters have been waging an international campaign to have those responsible brought to trial, but no one has been charged.
Both Sinn Fein and the IRA have offered support to the family, with the IRA publicly offering to shoot those involved and unprecedented republican calls for full co-operation with the authorities.
The McCartneys allege, however, that the republicans are not exerting genuine pressure on those involved to give full statements about the killing.
The new threat is highly unlikely to have come from the IRA itself, since that organisation continues to assert that it wishes to be helpful to the family.
The possibility exists, however, that some of those suspected of personal involvement are feeling the heat and anxious to discourage the continuation of the McCartney campaign.
The public attention devoted to the case fell during the recent election campaign, when the McCartney issue had at most a marginal influence on voters.
Earlier this week, however, the family scored a significant success in persuading the European Parliament to support any civil case the family might take against the suspects.
Paula McCartney said last night: "It's absolutely scandalous. It's dreadful that the victims of this whole episode are now being intimidated in such a way.
"We are very, very determined. Nobody will intimidate us. We will not rest until the murderers of Robert are brought before a court of law."Reuse content