Gerry Adams has made a formal complaint to the PSNI about aspects of his interrogation.
The Sinn Fein president was detained last week and questioned for four days about the abduction and murder of Jean McConville in 1972.
He's continually denied allegations that he ordered the killing of the west Belfast mother-of-10.
Mr Adams has described his arrest as a “sham”, and said no new evidence was produced during his detention.
