Police investigating the murder of Jean McConville have been given an additional 48 hours to question Sinn Fein leader Gerry Adams.
The 65-year-old, who has always vehemently denied allegations levelled by former republican colleagues that he ordered the murder of Ms McConville, voluntarily presented himself for interview on Wednesday.
His custody was extended on Friday night after Stormont Deputy First Minister Martin McGuinness claimed the detention of his long-time party colleague and friend was politically motivated ahead of elections later this month.
Ms McConville was dragged screaming from her home by an IRA gang in 1972 Mr McGuinness accused "very senior people" in the PSNI who were opposed to the peace process of engaging in "political policing".
"There is a cabal in the PSNI who have a different agenda - a negative and destructive agenda - to both the peace process and to Sinn Fein," he said.
Mr McGuinness contrasted the treatment of Mr Adams with a series of cases involving the British military - such as the Bloody Sunday killings of 1972 - where no action had been taken.
Mr McGuinness said Sinn Fein would "reflect" and "review" its support for policing in the region if Mr Adams is charged but urged republicans to remain calm if and until that happened.
Martin McGuinness says the arrest of Mr Adams was politically motivated Police are questioning Mr Adams about the killing of the Belfast mother of 10 in 1972.
She was wrongly suspected of being an informer to the British Army.
Ms McConville was dragged screaming from her children in the Divis flats in west Belfast by a gang of up to 12 men and women.
She was interrogated, shot in the back of the head and then secretly buried - so becoming one of the "Disappeared" victims of the Troubles.
A new mural of Gerry Adams is painted in Belfast's Falls Road Her body was not found until 2003 on a beach in Co Louth, 50 miles from her home.
Ms McConville's eldest daughter, Helen McKendry, has told journalists she is now prepared to name the people responsible for her mother's death.
PSNI chief constable Matt Baggott has vowed the investigation into Ms McConville's death will be "effective, objective and methodical".
No one has ever been charged with the murder of the 37-year-old widow.
Helen McKendry says she is ready to name the people who killed her mother But after years without progress in the criminal investigation there have been a series of arrests in recent weeks.
The recent police activity followed a decision by a US court compelling a Boston university to hand over to the Police Service of Northern Ireland (PSNI) recorded interviews with republicans about the murder.
Boston College interviewed a number of former paramilitaries about the Troubles on the understanding transcripts would not be published until after their deaths.
But that undertaking was rendered ineffective when the court ordered last year that tapes that contained claims about the killing be given to detectives.
The prison van carrying Clifford
Judge Leonard condemned Clifford's 'contemptuous' behaviour
Michael Schumacher and Nigel Stepney in 2001
There have been 400 cases worldwide. Pic: NIAID
The man travelled on a British Airways plane from Saudi Arabia to Heathrow
It is thought that coronavirus may have come from camels
DCI Gary Cunningham of Police Scotland speaks at a news conference
A group of photographers chase after the prison van carrying Clifford
During his trial, Clifford branded his victims 'liars' and 'fantasists'
Clifford's behaviour in this Sky News clip was branded 'extraordinary'
Clifford held his hands in his pockets as he posed for pictures at court
Mrs Maguire's family read some of the tributes to her outside the school
Mrs Maguire was stabbed as she taught at Corpus Christi Catholic College
Headteacher Steve Mort reads messages attached to bouquets of flowers
Gary Clarence, centre, at court last week
Mr Osborne says the figures show Britain is "coming back"
The hashtag #thankyouteacher has attracted a flood of posts
Tributes have been left at the school gates as well as on social media
Headteacher Steve Mort and pupils lay flowers in honour of Ms Maguire
Pupils have been leaving tributes and photographs outside the school 
The school community has been stunned by the murder of the popular teacher
Monsignor Paul Fisher conducted a mass at Corpus Christ Catholic Church
Head teacher Steve Moat and students lay flowers in church
Some 30 pupils are understood to have witnessed the killing
Pupils arrive at Corpus Christi College which opened as normal this morning
The woman suffered the fall at Wells Cathedral
The cathedral is in Somerset
Janet Marsh says it is an 'incredibly serious situation'
Sir Cyril's family has always denied the allegations against him
Max Clifford getting into his car after the verdicts
Clifford has described the charges as a 'nightmare'
The trial heard from Clifford's daughter Louise who said he was 'her rock'
Flowers left outside RAF Odiham in Hampshire
The aircraft went down in the Takhta Pul district of Kandahar
Lynx helicopters are deployed for a wide variety of operations
Simon Cowell and Harry Hill at the opening of the show in March
A poll suggests Nigel Farage has not been damaged by recent controversies