A man has been arrested in Co Donegal in connection with the murder of Denis Donaldson.

Donaldson, a senior Sinn Féin official, was shot dead at an isolated cottage near Glenties in Co Donegal in April 2006.

The 55-year-old had been living there since his exposure as an MI5 agent the previous year.

Gardaí today arrested a man in his 40s in connection with the killing. He is being held at Letterkenny Garda Station.

Gardaí are appealing to anyone who may have information in relation to this investigation to contact them at the Incident Room at Letterkenny Garda Station at 074 9167100, the Garda Confidential Line at 1800-666-111 or any garda station.