Published Saturday, 27 February 2010
Kieran Doherty, 31, who was shot in the head, was left stripped and tied up in a remote laneway close to the border with the Republic of Ireland on Wednesday night.
A family statement released to local journalist Eamon McCann insists that Mr Doherty wasn't a criminal.
"The family strongly reject and resent the suggestion that Kieran was in any way involved in drugs", Mr McCann told UTV.
They also claim that he had been under "continuous harassment" from the secret service MI5 in the months before his death.
The victim, from the Brandywell area of Londonderry, was the father of a two-year-old daughter and was due to marry his partner, Mairead, in three months.
The family admitted he had served time in prison, reportedly for a robbery in Co Donegal, but claimed he had been trying to get on with his life.
"He was neither an informer nor a criminal. He was never in his life associated with drugs", the family statement says.
"Kieran was under continuous harassment by MI5 in the months before his death".
"Repeated attempts were made to recruit him as an informer. He rejected all these attempts," the family also alleged.
They have called for a police inquiry into MI5's involvement with Mr Doherty.
The statement added:
"Kieran was a good and decent man trying to lead a normal life, looking forward to getting married."
They said that in the last months of his life Mr Doherty was stressed and had lost weight.
They said he was treated in hospital for depression and was sometimes almost unable to speak to his partner.
On Friday police confirmed post-mortem reports suggested he died from gunshot wounds.
His body has been returned to his family.