SINN Féin leader Gerry Adams will not be charged in connection with the disappearance and murder of mother-of-10 Jean McConville.
The party president was questioned over four days in May last year by detectives investigating the abduction of the west Belfast woman in 1972.
Her body was secretly buried and only found on a beach in Co Louth in 2003.
Mr Adams was questioned on the basis of allegations contained in controversial Boston College recordings secured by the PSNI.
Interviews were carried out with former paramilitary figures on the understanding they would not be revealed until after their deaths, but tapes were handed over to police following legal action in the United States.
Mr Adams said at the time there was a "sustained, malicious, untruthful campaign" alleging his involvement in the 1972 killing.
One man, veteran republican Ivor Bell, has been charged in connection with the case.
The 78-year-old is accused of aiding and abetting the murder of the 37-year-old widow based on information allegedly revealed in a recorded interview lodged with Boston College.
A file in relation to Gerry Adams was sent to the Public Prosecution Service for consideration in May 2014.
The case was reviewed by a senior prosecutor, with Director of Public Prosecutions Barra McGrory excusing himself from the case because he previously represented Mr Adams during his time in private practice.
However, The Irish News understands that after considering the evidence contained on the tapes a decision has been made not to prosecute.
A legal source said while prosecutors are confident that the alleged confessions made by Bell meet the test for prosecution, the evidence against Gerry Adams was uncorroborated allegations which fall short of that standard.
The decision not to prosecute is expected to be announced by the PPS within days.
