The eldest daughter of Jean McConville has vowed to name her mother's killers.
Helen McKendry, who along with her nine siblings watched their mother dragged away screaming by the IRA, said she is no longer afraid.
"I spent the first 20 years of my life being afraid of these people, of fearing to speak out, but now I am no longer afraid," she told the Guardian.
"If full cooperation into the murder of my mother includes naming those who I saw bursting into our flat, who dragged my mother away from us at gunpoint, and who were directly involved in her disappearance and murder, then yes, I would be prepared to name names.
"To me that is not informing but doing my duty to my mother."
Helen's husband Seamus also slammed Deputy First Minister Martin McGuinness's claims of a police conspiracy against Sinn Fein as "totally absurd and a deep insult to the family and the wider community's intelligence".
"This is the same PSNI which Martin McGuinness asked everyone, including his own supporters, to endorse when devolution was restored," he said.
"He can't have it both ways. This is just typical spin to deflect from the real story behind all of this, to deflect from the terrible crime inflicted on Jean."
Meanwhile, Helen's brother Michael said the murder and secret burial of their mother meant any trial should be treated as a war crime and held in the International Criminal Court.
"These people should be brought to court in The Hague for war crimes because that's what this is," he said.
Gerry Adams arrest: Sinn Fein leader remains in police custody - quizzed over Jean McConville murder
"This happened in the Second World War and Bosnia – the people who took people out into the woods and shot them and secretly burying them were brought up for war crimes."
Responding to claims by Sinn Fein that the arrest of Mr Adams has not made much impact on the electorate in the Republic, Mr McConville said: "I thought it would have sparked a lot of interest down South.
"I would have thought it would have brought a lot of pressure.
"But I think the South is probably fed up of all the Troubles up here."