The family of a Catholic taxi-driver shot dead in Co Tyrone have blamed the Provisional IRA for the killing.
They claimed it was linked to a fight between Barney McDonald (52) and a local IRA commander.
A statement in the name of the loyalist Red Hand Commanders has admitted responsibility and Sinn Féin has denied the IRA was behind the murder.
However, speaking to The Irish Times, the McDonalds last night accused Sinn Féin of "lies and hypocrisy".
Local sources believed the killers deliberately used shotguns because the weapons cannot easily be traced through ballistic tests.
Mr McDonald, a father of eight, was called to pick up a fare at Arthur's snooker club in Annaghbeg Park in Donaghmore at 11 p.m. on Wednesday.
Two men, lying in wait, opened fire with the two shotguns. The victim was hit in the head and died instantly.
The Police Service of Northern Ireland said it had not yet established a motive for the killing. Chief Supt Eddie Graham said detectives were keen to locate the getaway car.
Loyalist involvement has not been ruled out. Local people said there had been tensions between members of the family and a Protestant-owned taxi depot.
In a statement to a Belfast newsroom, the Red Hand Defenders admitted responsibility but security sources said they were keeping an open mind. "Loyalist involvement is entirely possible but this statement must be treated with caution because the Red Hand Defenders claimed responsibility for shooting a drug dealer in Coalisland last year when it was actually the IRA involved," a source said.
There is a history of conflict between the Provisional IRA and the family. Mr McDonald's daughter, Alicia, said the organisation had recently threatened her father's life.
The killing was linked to a fight six weeks ago between her father and a local IRA commander, she claimed. "The Provos have long held a grudge against my family. My brother Brian was in a bar playing pool last month when he was followed outside by three Provos who acted in an intimidating way. My father tackled them about it. A fight developed and one of the Provos was hurt."
The senior IRA commander was in hospital for three days recovering from his injuries, according to local people. They said the man and his unit were deeply embarrassed by the incident and were set on revenge. "People knew something would happen to Barney but we expected him to get a beating, not be killed" one man said.
Ms McDonald said the Provisional IRA visited the home of her father's girlfriend afterwards. "They told her to tell him they were the real IRA, they would sort him out, and he would soon know about it."
Local Sinn Féin MP Mr Martin McGuinness offered his condolences to the family and said he shared the community's shock . Sinn Féin Assembly member Mr Francie Molloy said he was unsure whether the killing was sectarian but he was certain republicans were not involved.
SDLP councillor Mr Vincent Currie condemned this "cold-blooded, cruel and callous" murder.
"Barney was a well-respected, hard-working fellow who provided a vital community service with his taxi. He was a hard man who would defend his family but never went looking for trouble."
Mr McDonald's son, Paul, was badly injured in an IRA punishment attack two years ago. He died in a car crash a month later. Another son, Eugene, was killed in a car crash eight years ago and Mr McDonald's wife died last year.