Cameron Martin, 47, was found dead after his Mercedes Benz collided with a tree off Tallebudgera Creek Road on Friday night.

But the post mortem examinations revealed he'd died from a gunshot wound to the chest, not as a result of the accident.

An autopsy also showed that 36-year-old Shane Ross who was found dead in bushland on the corner of the Pacific Highway and Tallebudgera Creek Road on Monday, was also shot.

Police would not confirm the calibre of the weapon or if bullet casings had been found.

Ross, a Comanchero and, founder of Monstr Clothing, had last been seen with Martin and two other men at a Pimpama tavern about 7pm on Friday.

They had met for drinks before Ross and Martin left in a dark coloured vehicle for a meeting in a Tallebudgera park.

Two hours later, Martin, who had changed cars, was dead, shot in the chest with his car crashed into a tree.

Ross was reported missing on Sunday before his body was found by friends in long grass about one kilometre away.

He had a gunshot wound to the head, but it is not yet known when he died.

It is not known if Martin was in the park with Ross, 36, when he was killed, or if he witnessed the shooting, but police are certain the deaths are connected.

Witnesses reported the injured third man was seen in the area of the crash and police have described him as a person of interest.

"We have still not identified the man seen staggering along Tallebudgera Creek." Regional Crime Co-ordinator Kerry Johnson said.

"We do not know if they were injured, wounded, intoxicated - we don't know whether they are even involved but we still have to try and find that person to rule out or rule in that line of inquiry."

He maintained the deaths were a "contained incident" and there was no risk to the public.

Police are appealing for anyone with dashcam footage of a white c200 Mercedes between 8pm to 10pm or information to contact detectives.

Australian Associated Press