Victims' campaigner Willie Frazer has attempted to serve a High Court writ at the South Armagh farm of prominent republican Thomas 'Slab' Murphy.
Mr Frazer is claiming damages for the murder of his father, a part-time UDR soldier, who was shot dead at Whitecross in August 1975.
Mr Frazer told UTV the move was part of his campaign to get justice for hundreds of victims of IRA violence.
"Today victims have taken the first step in the fight for justice," Mr Frazer, the founder of the pressure group Families Acting for Innocent Relatives, said.
"This will not be the last writ served and we will continue to fight for truth and justice.
"We will not rest until we make our streets a safer place," he added.
In 1985, Slab Murphy was accused by the Sunday Times of directing an IRA bombing campaign in Britain.
In 1987, he unsuccessfully sued the paper for libel in Dublin.
He also lost the retrial held in May 1998.
Murphy, who is also widely believed to be a former Chief of Staff of the IRA, eventually dropped the case in 1999.
He has paid out hundreds of thousands of pounds in legal settlement following investigations by the Criminal Assets Bureau in the Republic of Ireland and the UK's serious organised Crime Agency.
"I made a commitment that I would do everything in my power to hold the godfathers responsible," Mr Frazer said.
"We can't go after every individual, but we can go after the godfathers and this is the first of at least half a dozen writs which will be served."
There was no sign of Thomas 'Slab' Murphy at the yard, outside Crossmaglen.
Mr Frazer left the writ in the cab of a lorry in the yard.
The prominent republican has 14 days to respond.
© UTV News