JEAN McConville's family have accused Sinn Féin leader Gerry Adams of being "two-faced" after he described the horrific abduction and murder of the mother of 10 as something that "happens in war".
Speaking to a primetime US television show, Mr Adams also said Ms McConville's murder was no different to what occurred in conflicts involving US and British armed forces.
Reacting to his comments angrily, Seamus McKendry, the husband of Ms McConville's daughter Helen, said he and his wife had become accustomed to Mr Adams's "callous" remarks about the young woman's savage murder at the hands of the IRA.
Mr McKendry said Mr Adams had a "brass neck" supporting victims of the 1971 Ballymurphy massacre, which saw 11 civilians brutally shot down by the British soldiers, while claiming Ms McConville was a victim of a war.
"Don't get me wrong, the Ballymurphy families are entitled to the truth and compensation but he's two-faced and nothing short of it," Mr McKendry told the Irish Independent.
Ms McConville was taken from her family home in front of her children and murdered by the IRA in 1972.
Mr Adams was arrested last year for questioning in connection with the young woman's murder and disappearance. He was later released without charge.
In an interview with CBS's '60 Minutes', Mr Adams was asked about his arrest and the Boston College tapes, in which former IRA members alleged he was involved in Ms McConville's murder.
"I was sick, sore and tired of a tsunami of stories based on these tapes linking me to Mrs McConville's death. So I contacted the police and said, 'Look you want to talk to me, I'm here to talk," Mr Adams told the show.
Mr Adams was held for four days and asked to listen to the Boston College recordings.
In a preview of the show due to be aired on Sunday, interviewer Scott Pelley then asked Mr Adams: "How do you orphan 10 children, what kind of depravity is that?"
Mr Adams responded: "That's what happens in war, Scott. That's not to minimise it. That's what American soldiers do, British soldiers do, Irish republican soldiers do, you know. That's what happens in every single conflict"
The Sinn Féin leader yesterday sought to defend his comments by insisting he gave a "very forthright and frank interview to CBS".