SDLP Leader Colum Eastwood has expressed his sympathy and offered his condolences to the family of Glenn Barr.
Mr Eastwood said: “I was saddened to hear of the death of Glenn Barr and wish to express my deep sympathy to his family and friends and to the broader loyalist community in Derry.
“Obviously Glenn’s early life began with a belief in violence which my party stood so strongly against, but it is right to acknowledge that he came to embrace and work for reconciliation and peace.
“That commitment was evident in his friendships across party lines and across the island of Ireland.
“Glenn’s passion and his ultimate legacy was in renewing the modern memory towards the nationalists and unionists who died side by side in the horrors of the First World War.
“Glenn was one of those behind the events which brought together Irish Presidents and the British monarchy in Messines to remember in dignity all of our dead.
“May he rest in peace.”