Detectives investigating the murder of Philip Smith today revealed he was a drug dealer whose criminal lifestyle probably led to his death.

Two months after his body was discovered in a rural Bradford lay-by, officers confirmed the dad-of-one had been "heavily involved" in the drugs trade and had likely gone to the isolated spot to meet a known associate.

But whoever Mr Smith encountered in Tong Lane, Tong, shot him twice in the head from close range and left him laying face down by his blue Audi A4.

The body of the weight training enthusiast and small-time car dealer was found by a passer-by the following morning, on February 20. The 29-year-old, from Highfield Road, Pudsey, left a girlfriend and 16-month old son Morgan.

Today, Detective Superintendent Allan Doherty - the officer heading the murder hunt - said Mr Smith had used a network of contacts, including people he knew from various gyms and his car-dealing business, to distribute drugs in Bradford and Leeds.

Det Supt Doherty appealed for Mr Smith's associates to come forward or run the risk of being arrested or even becoming his murderer's next target.

"I have been frustrated by the progress we have made because these people have been reluctant to come forward and be frank with us," said Det Supt Doherty.

He stressed the inquiry was focused on tracing Mr Smith's killer and added: "People should not let criminal activity get in the way of this. They should think of Mr Smith and those he has left behind."

He described the inquiry as a "massive jigsaw puzzle" in which his many contacts - both legitimate and criminal - needed to be eliminated. He was known to have many friends in the Woodside area where he had lived most of his life.

Det Supt Doherty said: "For those people who have not been willing to come forward or who have not been frank with us, we have found it necessary to arrest them."

Detectives had already quizzed four people this way, said Supt Det Doherty.

And those linked with Mr Smith who did not co-operate would have their private lives "thoroughly examined", with the risk of uncovering unrelated criminal behaviour, he added.

"Despite the fact that he was dealing in drugs, Mr Smith did not deserve to die like he did. It was a brutal, cold-blooded murder which has left his young son a future of never knowing his father.

"I do not want him to face the prospect of knowing his father's murderer had not been caught."

And he added: "There is a very strong chance that, if they get away with it, whoever did this will do so again. What I would say to Mr Smith's criminal associates is: how do you know that you will not be next?

"Come forward and help put these people behind bars."

Anyone with information should call the incident room on (01274) 373133 or Crimestoppers on 0800 555111.