Police in Northern Ireland are questioning an alleged IRA double agent about two paramilitary murders in the Newry area of Co Down in 1990.
The 46-year-old man, known as Kevin Fulton, was a former British soldier who infiltrated the IRA and became a double agent.
He was arrested by the Metropolitan Police in southeast London yesterday and flown to Belfast.
He is being questioned in the serious crime suite at Antrim Police Station about two murders in the Newry area of Co Down in 1990.
In one of the incidents, 23-year-old Eoin Morley, a member of the IPLO, was shot dead by the IRA.
In the other, Irish Ranger Cyril Smith was killed after an IRA car bomb was driven into a border vehicle checkpoint at Killeen and exploded.
It is thought the arrest of Kevin Fulton may have been requested by the PSNI's Historical Inquiries Team.
It is examining 3,000 murders committed between 1969 and the signing of the Good Friday Agreement, in an attempt to establish if new evidence can be established and charges brought.