Murder squad detectives believe a long-standing grudge might be behind the cold-blooded execution-style killing of a Bradford family man.

And they are investigating whether the shooting of dad-of-one Damian Gordon could have any links to previous violent incidents involving gangsters from Manchester.

West Yorkshire detectives are making intensive inquiries in Manchester and believe a mystery woman caller from that area could hold the key to finding the murderers who gunned down the defenceless father as he fled a Bradford night club.

Mr Gordon, 30, of Swain House, Bradford, had enjoyed a family outing with his wife and four-year-old son only hours before he was killed.

His devastated wife yesterday pleaded with the public to help police find the murderers.

Police have stressed that Mr Gordon was not known to police and had no previous convictions.

But they are looking into suggestions that he may have been the victim of a grudge and was gunned down by someone from Manchester.

A number of people from the city are known to have been in Club Icon, at the junction of Westgate and Drewton Road close to Bradford city centre, when Mr Gordon was shot.

West Yorkshire detectives have been in Manchester for the last two days liaising with colleagues there and following up positive clues.

Detective Superintendent Paul Taylor, who is leading the murder hunt, urged a woman, believed to be from Manchester, who anonymously called police within hours of the shooting to get back in touch.

“She gave us very specific information which could be very significant to this inquiry,” said Det Supt Taylor.

He said dozens of people had been in Club Icon, which is mainly used by the Afro-Caribbean community, at the time of the killing and urged them to come forward.

The incident has similarities to a series of violent incidents that happened close to another Afro-Caribbean club, Funktions, only yards away in Hallfield Road in 2005. The club was closed after two shootings, a stabbing and several assaults in the vicinity.

Det Supt Taylor said: “We are aware of previous incidents and we are trying to establish if there is any link.”

Mr Gordon was shot dead with a handgun and police officers were yesterday searching nearby drains for the murder weapon.

The club is likely to be closed for several days while a painstaking forensic examination takes place. Officers are also studying hours of CCTV footage and are looking to trace any vehicles which left the scene.

Police were alerted to the shooting at 3.30am on Sunday and found Mr Gordon lying with gunshot wounds face down outside the building. He was taken to Bradford Royal Infirmary but was pronounced dead.

Detectives say the killing does not appear to be linked to other recent violent crimes in the city and have emphasised there is nothing to suggest Mr Gordon had anything to do with drug dealing or other criminal activities.

Det Supt Taylor said: “This was a brutal attack on a defenceless family man who was unarmed.”

Police believe Mr Gordon, who was known as Mikey, was fleeing the premises when he collapsed just outside the entrance, but it is not clear whether he was shot before leaving or after.

A number of shots were fired but it is unclear how many.

The motive for the shooting remains unclear but Det Supt Taylor said: “Clearly something triggered this murder, possibly something that happened within the club, which Mr Gordon had visited that night. We need to build up a picture of what that event was.”

He said dozens of people had been in the club but very few had come forward with information.

“Whatever happened has started inside the club and spilled outside. There were lots of people in the club and some would have been with Mr Gordon. We need anyone who was at the club at that time to come forward."

Club Icon opened around three to four years ago in first floor premises formerly occupied by the Harmony Ballroom dance academy.

The current licensee is Gillian Gordon – who is not related to the victim.

A Bradford Council spokesman said there had been some variations in opening times at Club Icon since the Council took over responsibility for licensing in November 2005.

The latest change was an extension to the club’s hours for selling alcohol, granted in May. It can now open to sell alcohol between 7pm and 6am every day of the week. The spokesman said there had been no issues with the club’s licence.