Robert Harple, 33, of Westfield Terrace, was playing pool with friends when he suddenly dropped his beer glass and fell rigid to the floor.

Hospital staff tried in vain to revive him for two hours but he died on February 22 this year.

Small amounts of alcohol and cocaine were found in his blood but consultant pathologist Dr Olorunda Rotimi told an inquest in Leeds these were unlikely to have caused his death. He said it was impossible to ascertain the reason.

"In five per cent of autopsies, we can find no cause," he explained.
He agreed with assistant deputy coroner Kevin McLoughlin that cocaine use might be a complete red herring and there might have been an electrical abnormality in the heart which would not show up on autopsy.

Dr Rimini said disturbances in these electrical connections were sometimes the cause of athletes' sudden deaths.

Robert's long-time friend Anthony Phipps said they had gone out to the Supa Snooker club in Templer Lane, Leeds, and were chatting, drinking, watching TV and playing pool.

"Rob was behind me and suddenly dropped his beer," he said. "I heard it
smash and turned round and he appeared to be stiff and went straight down on the floor. He didn't attempt to break his fall and his eyes never opened. I checked his mouth to see if he had swallowed his tongue." He then had three convulsions before paramedics arrived.

Paul Maddison, another friend, said that Robert was into sport – cycling, medium distance running, basketball, golf and squash.

He knew he was a social user of cocaine, but added: "I wouldn't even suggest he was addicted, He kept cocaine in a tobacco pouch and when I checked it at the hospital there was none inside. He would use it to perk himself up if he went to nightclubs."

Mr Maddison said Robert had everything to live for. He had just got a new job with a drain cleaning company; he was happy with his girlfriend Melanie; and he was hoping to buy a house.

Mr McLoughlin said the death was a mystery and he recorded a narrative verdict which simply set out the known facts. "We are not in a position to say if he died of natural causes," he added, "and an open verdict would leave things hanging."