MYSTERY may forever surround the death of a man killed on the M4 just over a year ago.

The body of Clive Preedy, 35, of Toothill, was found on the M4 motorway between junctions 15 and 16 in the early hours of February 22 last year.

He had died of multiple injuries apparently after being struck by several vehicles on the westbound carriageway.

A major police investigation, dubbed Operation Deacon, was set up and tracked his last movements to a footbridge over the M4 between Croft Road and Hay Lane, but the investigation was unable to ascertain why his body was found nearly a mile further west near the Mill Lane bridge off Wharf Road in Wroughton. Yesterday Wiltshire coroner David Masters gave an open verdict on the death of Mr Preedy saying there were too many missing details to define either a suicide or accidental death.

Yesterday, his mother, Rita Todhunter, who was the last person to see Clive alive, paid tribute to her son and accepted the fact that vital clues to what happened to him will probably never been known.

She said: "I am satisfied with what the coroner has said. We just don't know what happened, and no-one ever will.

"I know that he would never have committed suicide, he had a lust for life, he loved the natural world and the environment.

"He was kind caring and would do anything for anybody, he is much missed by all of us."

The inquest heard how Mr Preedy would often take long walks late at night, usually taking his dog Sadie, but on the night of the accident he didn't take his pet and embarked on the four-mile walk alone. The inquest heard a statement from lorry driver Michael Moore who was driving along the M4 that morning.

He said: "I was driving along with dipped headlights, when I caught something lying in the road in the lights, I had no time to brake or swerve and I felt a bump as it went between the wheels."

Mr Moore parked his vehicle, donned a fluorescent vest and grabbed a torch and his phone and went back to see what he had hit. When he found the body he tried to wave traffic off, but a van and a saloon car also ran the body over.

Police officers said there was a distinct smell of alcohol on Mr Preedy's clothes, but he did not drink and toxicology reports found there was no alcohol in his bloodstream.

They also found that Mr Preedy's body was hit some 20 metres away from the Mill Lane overbridge, and officers felt it was impossible for him to have fallen that distance.

A police tracker dog was bought in from Dyfed-Powys Police force and tracked the route Mr Preedy took from his Toothill home to the M4. Using a scent from a pillow case the dog took officers all the way to the footbridge north of the Ridgeway School, but the dog was unable to find a strong enough scent after that point.

Mr Masters said: "I am recording an open verdict, because I just do not have that last piece of the jigsaw to complete the evidence and I know the police have worked hard to close that gap, but we will never really know what happened that day."