Irish police have released a man without charge after arresting him in connection with the murder of Andrew Allen.
The man, who is in his 40s, was released on Thursday evening.
The father of two from Londonderry was shot dead in February 2012 at a house near Buncrana, County Donegal.
Republican Action Against Drugs (RAAD) admitted responsibility for the murder. Mr Allen's family have always denied claims he was a drug dealer.