POLICE investigating the murder of SAS officer Captain Robert Nairac in Northern Ireland more than 30 years ago have arrested a man in South Armagh.

The suspect, aged 57, was detained by officers from the Police Service of Northern Ireland serious crime branch and taken for questioning in Antrim, the force said.

Captain Nairac, a graduate of Lincoln College, Oxford, was abducted by the IRA, taken across the border into the Irish Republic and shot. His body has never been recovered.

Six people were convicted for their part in the killing of the army officer, who was abducted on May 14, 1977, when he visited a pub at Drumintee, South Armagh.

He was seized during a struggle in the pub's car park and taken across the border to a field at Ravensdale, County Louth, where he was interrogated for more than an hour and then shot dead.

Five of those convicted were from Northern Ireland and one from the Republic.

But police believe three other members of the IRA gang were involved.

It is understood two of them are living in the United States.