The death of a man found critically injured in the street sparked a murder inquiry after a trauma doctor told police his injuries were too serious to have been caused by a fall.

A doctor feared Robert Wellstead, 56, had been attacked or hit by a car after he was found face down outside his home in Oxford Road, Wincheap.

But an inquest into his death this week heard that the doctor’s assessment had been wrong.

The hearing was told a post-mortem examination revealed his death had been caused by a cardiac arrest, which starved his brain of oxygen and likely led him to collapse and hit his head on December 4, 2013.

Police and paramedics battled to revive him and he was taken to King’s College Hospital in London, but died five days later.

At the inquest, Det Sgt Chris Greenstreet said Mr Wellstead’s family was initially told he may have been injured as a result of an assault or by a hit and run driver.

He said: “Inquiries continued while he was still critical because the doctor’s assessment that his injuries were too serious to have resulted from a fall from ground height had been contrary to other medical professionals.

“Major crime took over the investigation and there were house-to-house inquiries and numerous witnesses spoken to.”

Mr Wellstead, who was a carer for his disabled mother, had been drinking at the Run of the Mill pub in Sturry Road that night and was dropped off by a taxi driver in Oxford Road shortly before midnight.

An hour later he was seen face down in the road by the driver of a passing car, student Haja Bangura. In her statement, she said Mr Wellstead was lying in a pool of blood so a friend dialled 999.

The first police officer on the scene was dog handler PC Paul Donovan, who carried out CPR.

He and paramedics fought for almost an hour and managed to gain a pulse, after which Mr Wellstead was taken to London by air ambulance.

Det Sgt Greenstreet said officers were concerned about the unaccounted hour between Mr Wellstead being dropped off at home and being found in the street.

But he said the answers had been provided by neighbour Eleanor Martin, who told them she would often see Mr Wellstead outside his house in the street late at night having a cigarette.

Another neighbour and friend, Sabrina Jones, said he was a heavy drinker and had been admitted to hospital on several occasions and had fallen before.

“The ultimate cause of death was natural, caused by underlying heart disease. I can definitely rule out any third party involvement" - assistant coroner James Dillon

In his report to the inquest pathologist Dr Ashley Fegan-Earl said there were no injuries which suggested Mr Wellstead has been assaulted or hit by a car.

His broken ribs had been caused by vigorous chest compressions, which was commonly the result of CPR. But he found he had heart disease which could have caused the cardiac arrest.

Recording a narrative verdict, assistant coroner James Dillon concluded: “The ultimate cause of death was natural, caused by underlying heart disease. I can definitely rule out any third party involvement.”

After the hearing, Mr Wellstead’s sister, Shirley Wilkie, of South Canterbury Road, said: “It was a real shock when we heard they were treating Bob’s death as a possible murder.

"But it’s just a relief that was not the case and we can put it all behind us now and move on.”