Police investigating the abduction and murder of Jean McConville in 1972 have arrested a 77-year-old man in west Belfast.
The suspect has been taken to the Serious Crime Suite at Antrim Police Station for questioning by detectives from Serious Crime Branch.
It's believed the man arrested is veteran republican Ivor Bell.
37-year-old Mrs McConville, a widow and mother of 10 children, was abducted in December 1972 from her flat in the Divis area of west Belfast and shot by the IRA.
Police said they could not comment further on the arrest, but it is believed officers were acting on some sort of new information.
Ivor Bell is a former IRA commander in Belfast and was once a close republican associate of the Sinn Fein leader.
In 1972 he was part of a republican delegation which included Mr Adams and Martin McGuinness - the deputy Northern Ireland First Minister who was an IRA leader in Derry at the time - who were flown to London by the RAF to have secret ceasefire talks with British Government minister.
Jean McConville became known as one of the Disappeared - those who were abducted, murdered and secretly buried by republicans during the Troubles.
Members of the IRA claimed some of the victims had "informed" on their activities to the authorities.
Mrs McConville's remains were finally found at Shelling Hill beach in Co Louth in the Republic in August 2003.
In November last year Deputy First Minister Martin McGuinness appealed for anybody with information about undiscovered remains of the "Disappeared" to give it to somebody in authority.
The PSNI also made a fresh appeal to a man who phoned the McConville family in the mid to late 1990s, claiming he had been involved in the abduction, to come forward.
A teenager at the time, he said he had been told to steal a van which was used to take Mrs McConville away. He claimed he drove her to a house in another part of west Belfast and left.
Police have said he moved to England some time after, and said he only found out later Mrs McConville had been murdered.
Michael McConville, who was 11 when his mother was snatched from her west Belfast home in 1972, was abducted, beaten and threatened at gunpoint by young republicans intent on keeping her disappearance quiet.
Even though a former IRA boss claimed Sinn Fein president Gerry Adams ordered her murder, he insisted in a special television documentary that he had nothing to do with the young mother's death.
10 were left orphaned by mother's murder
Michael McConville was 11 when his mother was snatched from her west Belfast home in 1972.
She was abducted, beaten and threatened at gunpoint by young republicans intent on keeping her disappearance quiet. Mrs McConville, a widowed mother-of-10, was among 16 people abducted, killed and secretly buried by republican paramilitaries during the Troubles.
The widow's remains were recovered at Shelling Beach, Co Louth, in August 2003. Forensic tests revealed she had been badly beaten and shot in the back of the head.
"If I lived for 200 years I still don't think I could describe how I felt when we got my mother's body back," Mr McConville, who wants the killers brought to justice, told the documentary.
"That was a war crime and the people responsible should be brought to The Hague."
Despite the passage of over 40 years, Mr McConville, now aged 51 and a father-of-four, can still vividly recall the day his mother was dragged from her home.
Before her death Jean McConville was held and interrogated for up to six days in Belfast. Separate teams of IRA volunteers were organised to drive her south of the Irish border, kill her and to dig the grave. Lies that she had been an informer who revealed the location of a gun or had stashed Army transmitters were circulated by the IRA.
Claims she had helped an injured British soldier were also spread among the staunchly republican community, and her orphans were shunned.
At least 16 people were disappeared during the Troubles, 15 believed to have been carried out by the IRA and one by the INLA.
Those who are still missing:
Kevin McKee and Seamus Wright -- missing since October 1972.
Seamus Ruddy -- missing since May 1985.
Columba McVeigh -- missing since November 1975.
Brendan Megraw --missing since April 1978.
Captain Robert Nairac -- missing since 1977.
Joe Lynskey -- disappeared in 1972.