Seamus Maguire is thought to have been killed and secretly buried by republican paramilitaries between 1973 and 1976.

Families of those secretly killed and buried by paramilitaries during the Troubles took part in their annual silent walk at Stormont.

The remains also do not belong to any member of the family who own the grave plot in Annyalla, Co Monaghan, investigators have said.

Relatives of people killed and secretly buried took part in their annual All Souls Day walk at Stormont

The British Army officer is believed to have been abducted by the Provisional IRA while on an undercover operation in a pub in south Armagh in 1977.