A Sinn Fein MLA has reacted angrily to claims that former Deputy First Minister and IRA "boss" Martin McGuinness directed the assassination of Lord Mountbatten almost 40 years ago.
Former IRA intelligence director Kieran Conway has no doubt about who was at the helm of the terror organisation when a bomb was detonated on Lord Mountbatten's fishing boat in Co Sligo on August 27, 1979.
"I wouldn't have said it until Martin died that McGuinness was chief of staff," he told a BBC documentary to be aired before the anniversary of the atrocity.
It has prompted Foyle MLA and former IRA H-Blocks commander Raymond McCartney to speak out in defence of his former comrade who died in March 2017 aged 66.
"It is reprehensible that anyone would make unfounded allegations against a man who is no longer here to defend himself," the ex-terrorist, who was himself the subject of a British spying operation in 2002, said.
"Kieran Conway clearly has no respect for himself or Martin McGuinness and more importantly for Martin's wife Bernie and the McGuinness family."
But Conway is adamant that the man who went on to play a pivotal role in the peace process took up the top IRA role a year before the assassination of Mountbatten.
When asked if the murderous act was ultimately McGuinness' responsibility, Mr Conway replies: "That's right, yeah."
"That's the way it works," he continued. "If you're the boss, you're the boss, you take responsibility for whatever goes on."
Mountbatten died alongside his grandson Nicholas and Fermanagh teenager Paul Maxwell (15) in the horror blast off Mullaghmore.
The 83-year-old Dowager Lady Brabourne died the following day.
On the same day the IRA murdered 18 soldiers in a double-bombing at Narrow Water Castle in Warrenpoint, which marked the biggest loss of military life in a single day during the Troubles. Civilian Michael Hudson was also killed when soldiers opened fire during the bloody massacre - he was birdwatching at the time.
In 2012 Mr McGuinness shook hands with the Queen - Lord Mountbatten's cousin - for the very first time after addressing her in Irish.
Mr McCartney, a former IRA hunger striker who served 17 years in prison following a double murder conviction which was later overturned, insisted Mr McGuinness' legacy is peace.
"Martin McGuinness' leadership and his record in challenging injustice and promoting peace and reconciliation is rightfully held in the highest of esteem across Ireland and internationally," he said.
The Day Mountbatten Died also features interviews with Lord Mountbatten's granddaughter India Hicks, who was prescribed Valium as a child following the traumatising attack on her grandfather. It will be broadcast on BBC One NI and BBC Two at 9pm on Monday.