A 75-year-old man arrested over a pub bombing in which 15 people were murdered in Northern Ireland has been released unconditionally.
The attack at McGurk's bar in Belfast on 4 December, 1971, was carried out by the loyalist paramilitary group, the Ulster Volunteer Force (UVF).
The man was detained in east Belfast on Wednesday but later freed.
Police recently reopened the case following a critical report into the original RUC murder investigation.
In the immediate aftermath of the attack, the IRA was blamed for placing the bomb.
In February 2011, the Northern Ireland Police Ombudsman published a report claiming the original Royal Ulster Constabulary (RUC) police investigation was "biased".
Following the publication, the Historical Enquiries Team, and more recently PSNI detectives in Serious Crime Branch, began a review of the case.
One man was convicted of all 15 murders in 1978.