A decision on whether to charge Gerry Adams over the abduction and murder of Jean McConville is expected within weeks, the Belfast Telegraph can reveal.
The Sinn Fein president was arrested on 30 April 2014 and questioned by police for four days before being released.
The PSNI file has now been presented to Northern Ireland's Public Prosecution Service (PPS), which will decide whether to charge the 65-year-old politician with any offence.
Mr Adams has always vehemently denied allegations levelled by former republican colleagues that he ordered the murder of the west Belfast widow in 1972.
A PPS spokeswoman told the Belfast Telegraph today the case is still under "active consideration" and a decision is expected within weeks.
Over a year has passed since Director of Public Prosecutions Barra McGrory QC delegated the case to his deputy, Pamela Atchison, because he had previously acted as Mr Adams' lawyer prior to becoming DPP.
However BBC reports have suggested there is "insufficient evidence" to pursue a prosecution.
Mr Adams' arrest triggered a major row at the heart of Northern Ireland's powersharing institutions, with Sinn Fein accusing an anti-peace process "rump" within the PSNI of orchestrating the arrest, branding it an example of "political policing" specifically timed to damage the party's chances in the forthcoming European and local government elections.
Those claims were emphatically rejected by Prime Minister David Cameron, Stormont First Minister Peter Robinson and Justice Minister David Ford.
Mrs McConville was dragged, screaming, away from her children in the Divis flats in west Belfast by a gang of up to 12 men and women after being wrongly accused of informing to the security forces.
She was interrogated, shot in the back of the head and then secretly buried - becoming one of the "Disappeared" victims of the Troubles. Her body was not found until 2003 on a beach in Co Louth, 50 miles from her home.
Earlier today, the PPS announced that Gerry Adams would not be prosecuted for allegedly withholding information about his paedophile brother.
Liam Adams was jailed for 16 years in 2013 for raping and abusing his elder daughter Aine Dahlstrom over a six-year period during the 1970s and 1980s.
1972: Mrs McConville is dragged screaming from her home in Divis flats in west Belfast by an IRA gang of around 12 men and women. It is the last time her children see her alive. She is shot in the back of the head and secretly buried, so becoming one of the 'Disappeared' victims of the Troubles. In the 42 years since no one has been charged with her murder.
1999: One year after the signing of the historic Good Friday peace accord in Northern Ireland, the IRA finally admits responsibility for killing the 37-year-old widow, claiming she was an informer for the British Army.
The Independent Commission for the Location of Victims' Remains is set up by the British and Irish governments and the IRA passes on information on Mrs McConville's possible whereabouts on a stretch of coastline in Co Louth. But subsequent searches by the Irish police fail to find her body.
2001: Academics, historians and journalists embark on a five-year project to collate an oral history of the Northern Ireland Troubles. The Boston College initiative involves interviewing former paramilitaries about their roles in the conflict on the understanding their accounts would not be made public until they die.
2003: The body of Mrs McConville is finally found by a dog walker on Shilling beach in Co Louth after a heavy storm exposes her remains.
2006: An investigation by Northern Ireland's then police ombudsman Nuala O'Loan rejects the IRA claim that Mrs McConville was an informer.
2008: Brendan Hughes, a former IRA commander in Belfast who was one of the figures interviewed for the Boston College project, dies.
2010: A book containing excerpts from Hughes's interviews is published. Among claims outlined in Voices from the Grave is the allegation that Gerry Adams ordered the murder of Mrs McConville. Mr Adams emphatically rejects the accusation.
In the same year Dolours Price, who was convicted of the IRA's bombing of the Old Bailey in 1973, makes similar allegations about Mr Adams. Price indicates that she has also spoken to researchers at Boston College.
Mr Adams again denies the claims and highlights both Price and Hughes' criticism of his and Sinn Fein's involvement in the peace process.
2011: The Police Service of Northern Ireland (PSNI) launches a legal bid in the US to try to obtain tapes within the Boston College archive that relate to the murder of Mrs McConville.
2013: Dolours Price dies in her Dublin home of a suspected overdose of prescription drugs.
Later in the year the PSNI wins it lengthy court battle with Boston College and a number of the tapes are handed over.
Veteran republican Ivor Bell, 77, from Ramoan Gardens in west Belfast, is arrested and charged with aiding and abetting the murder of Mrs McConville and IRA membership. His lawyer tells a court that the prosecution case against his client is based on an interview he allegedly gave to the Boston College project. The solicitor insists Bell will fight the charges.
Mr Adams, in response to the renewed focus on the McConville case in the wake of Bell's charges, issues a statement indicating he is willing to speak to the officers investigating the case. He again refutes any suggestion he had anything to do with the crime.
At different junctures through March and April, four women and one man, with ages ranging from 56 to 60, are also arrested and questioned about the murder. All five were subsequently released but police are preparing reports on the four women for the Public Prosecution Service to assess.
Mr Adams, after back and forth contacts between his lawyer and detectives, presents himself at Antrim police station for interview. He is immediately arrested and taken into custody - a move that Sinn Fein brands unnecessary and an example of "political policing".