A veteran republican was questioned tonight about the murder of Jean McConville - a mother of 10 abducted, shot dead and secretly buried by the IRA more than 40 years ago.
Ivor Malachy Bell, 77, was detained at his home in the Andersonstown area of west Belfast at lunchtime.
He was taken to the custody suite at Antrim to be interviewed by officers belonging to the Police Service of Northern Ireland's serious crime branch. Police refused to identify the man, but republican sources in the city confirmed it was Bell.
Mrs McConville, 37, was seized at her home at Divis Flats beside the Falls Road in Belfast by an IRA gang in December 1972, dragged a from her children after being accused of passing information to the British Army. An investigation later carried out by the Northern Ireland Police Ombudsman emphatically rejected the allegations.
Gerry Adams, the Sinn Fein president, has consistently denied having anything to do with her disappearance or that he belonged to the IRA - even though former disaffected members claimed he ordered the kidnapping.
Nobody has ever been charged with the murder, one of the most notorious in the history of the Northern Ireland troubles.
Police said they could not comment further on the arrest, but it is believed officers were acting on some sort of new information. 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.
A truce was called, but collapsed within days. Bell was interned in the high security Maze Prison, near Lisburn, Co Antrim, in February 1974. Just over two years later he escaped after swapping places with a visitor, but was recaptured a fortnight later while hiding in a flat in the Malone area of south Belfast.
Mrs McConville, was a Protestant who converted to Catholicism after she married a Catholic man, a former British soldier.
She was kidnapped by up to a dozen IRA men and women and later shot in the back of the head and then buried 50 miles from her home. The IRA did not admit her murder until 1999 when information was passed on to police in the Irish Republic.
She became one of the so-called Disappeared, but it was not until August 2003 when her remains were eventually found on Shelling Hill beach, Co.Louth.