A 45-year-old man has been arrested in Belfast on suspicion of murder.
It is understood the arrest is in connection with the killing of Reserve Policeman Constable Colin Carson in County Tyrone in 1983.
The man was detained on the Grosvenor Road in the west of the city shortly before 1430 BST on Friday.
The man, who was arrested under the Terrorism Act 2000, has been taken to Antrim police station for questioning.