A HAMPSHIRE businessman who was found dead in his Rolls Royce appears to have died from carbon monoxide poisoning, it has been revealed.

Detectives investigating the death of 53-year-old Norman Carlton say toxicology results indicate a "fatal inhalation" of carbon monoxide. But they said no hose pipe was attached to the exhaust of the car.

Mr Carlton, of Derby Road, Eastleigh, was discovered by a friend in the open boot of his champagne-coloured luxury car, which was parked outside Eastleigh civic offices on the morning of Sunday, March 6.

The Rolls Royce, which had a personalised number plate, was reversed against a hedge near the former magistrates' court building in a car park off Leigh Road.

The discovery of his body sparked a huge police operation, codenamed Operation Oryx, by the major crime department based at the police's western division headquarters in Hulse Road, Southampton.

But the investigation was later scaled down and switched to Eastleigh police station after officers said they were not seeking anybody else in connection with the death.

Mr Carlton was understood to have run the Call Carlton limousine hire company, based in Derby Road, Eastleigh, and was also believed to have been sleeping rough in his car and staying in hotels.

At the opening of an inquest into his death, Mid Hampshire Coroner Grahame Short heard that Mr Carlton was estranged from his wife.

Coroner's officer Roger Matcham said Mr Carlton had visited his home address on the night before he died.

The inquest opening also heard that closed circuit TV footage had revealed that Mr Carlton would have driven straight to the civic offices, which were just a few minutes from his home. He was discovered dead in his car at 9.40am the following day.

A full forensic investigation and a post-mortem initially failed to establish the precise cause of Mr Carlton's death and new toxicology tests were ordered.

Now detectives say the results of those tests indicate carbon monoxide poisoning and have shown no indication of prescription or "commonly abused drugs," including alcohol.

The inquest was adjourned until June 15 and the coroner's secretary said a report from the pathologist based on the toxicology reports was awaited.