The last pictures of the murdered biker Gerry Tobin were released by police yesterday as they appealed to Hell’s Angels not to carry out revenge attacks.

Closed-circuit television footage taken at a petrol station forecourt showed Mr Tobin looking relaxed and smiling as he made his final stop before being shot dead by a bullet to the back of the neck while riding on the M40 ten days ago.

Detectives have discovered evidence that two shots were fired from a green Rover 620, the second of which hit his motorcycle.

The last images show Mr Tobin, who was wearing a helmet, biker jacket and a plaid shirt, smile in the direction of the camera after he and fellow members of the Hell’s Angels group left the Bulldog Bash, an annual motorcycling event in Warwickshire.

Detective Superintendent Ken Lawrence, who is leading the investigation, said: “From Gerry’s demean-our, it doesn’t look as if he was aware anything was about to happen. He is not looking furtively around as if anybody is watching him. That suggests to me that he is not a man who feels under imminent serious threat.”

Mr Lawrence appealed to members of the biker group, which is noted for its reputation for lawlessness, to share information with police, and urged them not to take matters into their own hands. “I’m concerned that the Hell’s Angels are not coming forward and sharing what information they have with me,” he said.

“I’m sure they will have theories about Mr Tobin’s death and I’m asking them to share those with the police. I would like to enter into a meaningful dialogue with them but they are reluctant to do that.”

Mr Lawrence had said that he would be astonished if the murder had been carried out by another Hell’s Angel, because of the group’s code of loyalty, but that fringe elements could be tempted to retaliate. The murder of Mr Tobin, 35, who was born in Britain but grew up in Canada, has prompted fears of a violent feud between rival motorcycle gangs. Mr Lawrence said: “I would say, don’t even consider any retaliation – that would be entirely wrong. The law must deal with this.”

It is not known whether Mr Tobin had been singled out or was shot simply because he was wearing the Hell’s Angels insignia.

Police have received more than 500 calls from members of the public with information about the incident, and Mr Lawrence urged motorists who were on the M40 on the Sunday afternoon to report anything that they may think is important. He said that while it was difficult to be certain, he was “content” that the fatal shot had been fired from a green Rover 620 that was seen passing Mr Tobin at the time.

Motorists reported that the Rover was driven off at great speed immediately after the attack. Officers were studying CCTV images, including those of the Rover. Footage of the vehicle has been recovered but it does not show the numberplate.

The murdered biker’s mother has travelled from Canada to help police to build up information on Mr Tobin’s character and life.

Times Recommends

• Computer warriors pay for far-away mercenaries
• Divorce rate falls to 26-year low
• Boris adviser says Olympians tainted with blood