Police cordoned off the road after the fatal shooting
The murder of a man in north Down may be linked to a feud between loyalist paramilitaries over drugs, security sources have said.
Jim Johnston was shot dead as he shut the security gates outside his secluded luxury home on the Ballyrobert Road near Crawfordsburn at 2240 BST on Thursday.
A police spokesperson said it was believed two gunmen were involved in the shooting.
"These two individuals then made off on foot along the Ballyrobert Road in the direction of Belfast Road," said Superintendent Graham Shields.
Security sources have indicated the victim was well known within the world of loyalist paramilitaries and was a senior figure in the Red Hand Commando - an organisation with close ties to the Ulster Volunteer Force.
There were also suspicions of him having an involvement in drugs.
BBC Northern Ireland security editor Brian Rowan said some people within loyalism believed he would have been the target of other loyalists following the murder of Loyalist Volunteer Force leader Stephen Warnock in Newtownards last September.
Police have refused to comment on any possible links to drugs crime, with Detective Chief Inspector Roy McComb saying his sole concern was catching the two gunmen.
"Whatever people might think of Mr Johnston or anybody around him, that man's right to life was cruelly taken away from him," he said.
"That, and that alone, is what I am investigating - other issues are secondary in my view."
A senior member of the Progressive Unionist Party, which has links with the UVF, said he knew the man who was killed.
Assembly member Billy Hutchinson said the victim had raised concerns over his security.
Mr Hutchinson refused to speculate on who carried out the killing.
"We need to wait until the police make further investigations to see which quarter it came from."
Superintendent Graham appealed for anyone who was on the Ballyrobert Road between 2200 BST and 2300 BST to come forward.