A 56-year-old man detained by detectives investigating the IRA murder of Belfast mother-of-10 Jean McConville more than 40 years ago has been released.
Police said their inquiries were continuing.
The suspect was detained in west Belfast and taken to Antrim police station for questioning, a PSNI spokesman said earlier.
The abduction, murder and secret burial of Ms McConville in 1972 is one of the most notorious incidents of the Troubles.
Today's arrest came after a veteran republican - 77-year-old Ivor Bell - was charged last month in connection with the killing.
Mr Bell, from Ramoan Gardens in west Belfast, faces counts of aiding and abetting the murder and of IRA membership.
Ms McConville, a widow, was dragged away from her children in her home in the Divis Flats by an IRA gang of up to 12 men and women after being accused of passing information to the British army in Belfast.
An investigation later carried out by the Northern Ireland Police Ombudsman rejected the informer allegations.
Ms McConville was shot in the back of the head and buried 50 miles from her home. The IRA did not admit her murder until 1999, when information was passed on to gardaí.
She became one of the so-called Disappeared, and it was not until August 2003 that her remains were eventually found on Shelling Hill beach, Co Louth.
Nobody has ever been charged with her murder.