A 26-year-old man arrested by detectives investigating the murder of a policeman in Northern Ireland has been released without charge.
Constable Ronan Kerr died when a bomb exploded under his car at Omagh, Co Tyrone, on April 2.
Police investigating the attack arrested the man in Scotland four days later, before transferring him to Northern Ireland for questioning.
The Police Service of Northern Ireland has now said the 26-year-old has been released unconditionally.
A 40-year-old man was also later released while a 33-year-old man arrested in Northern Ireland in connection with the killing remains in police custody.
Constable Kerr, 25, was the victim of dissident republicans opposed to the peace process, though none of the extremist groups has yet claimed responsibility for his killing.
It is believed he was targeted because he was a Catholic, with dissidents keen to undermine the cross-community support for the new-look police service that replaced the Royal Ulster Constabulary (RUC).
In the aftermath of the young officer's murder, which sparked widespread condemnation, police uncovered a cache of weapons and explosives near Coalisland, Co Tyrone.
Police have warned that the dissidents remain determined to continue their campaign of violence, despite the growing calls for it to be brought to an end.