A man in his fifties who was detained at Buncrana Garda Station in relation to the murder of Derry man Andrew Allen, was released without charge this morning.
The man, believed to have been from the North, was arrested in Donegal on Friday morning.
Mr. Allen was shot dead at his home in Links View in Buncrana on 9 February. The vigilante group Republican Action Against Drugs later claimed responsibility for the killing.
To date, no further arrests have been made in relation to the shooting and no one has been prosecuted.