A drug-taking ski instructor was responsible for the death of a top cancer surgeon doctor who fell 750ft down an abyss while on holiday with his family, an inquest has been told.

Philippe Drigo was under the influence of cannabis when he agreed to put urology consultant William Choi in an advanced level group during a trip to the popular French alpine resort of La Plagne.

Later that day, dad-of-two Mr Choi, who lived in Littlebourne, was skiing off-piste with a group when he lost his skis and rolled down a steep slope.

His head struck a rock, which knocked off his helmet, before he continued to hurtle to the bottom of the Losset corridor.

Onlookers watched the harrowing incident unfold, with people rushing to help Mr Choi as he lay motionless.

Desperate efforts were made to revive the urologist, but he died a short time later having suffered traumatic neck and spinal injuries.

An inquest at Archbishop’s Palace in Maidstone heard how the instructor leading Mr Choi’s group, Philippe Drigo, has been convicted of involuntary manslaughter by French prosecutors. The guide appealed the decision but it was upheld by the courts.

Assistant coroner Sonia Hayes told the inquest the tragedy happened on March 21, 2016 - the first day of a planned week of skiing.

Experienced skier Mr Choi was described as a good level 2, and at the beginning of level 3 - considered to be an intermediate level. Skiers had been assessed on their skill in the morning and placed into groups.

But before lunch, the urologist asked to move into a higher group headed by Mr Drigo so he could ski faster.

The instructor, who had the responsibility of supervising eight people, believed Mr Choi was at level 3 and that he should join the group, saying the doctor had “underestimated” his own ability.

That day, Mr Choi had enjoyed lunch with his two sons, Alex and Xavier, his partner Abbey and her daughter Phoebe.

In the afternoon, he and seven others headed up the Losset corridor to the top of the 35-degree slope. Eyewitnesses told how Mr Choi had “listened and followed instructions” given by Mr Drigo.

He started travelling down the corridor at speed but his skis were caught on an outcrop, causing him to start tumbling.

His head struck a rock “shaped like a banana”, which caused him to lose his helmet from the impact and continue to plummet. By the time he stopped at the bottom of the corridor, he had fallen more than 750ft.

His fatal descent down the slope was caught on camera, with the footage later handed to authorities as part of the investigation.

A post-mortem revealed Mr Choi died from neck and spinal injuries known as craniocervical and thoracic trauma.

French police later questioned Mr Drigo, who denied taking drugs or alcohol. But he was found to be under the influence of cannabis, which the inquest heard could have impacted his judgement.

“When William fell I could not do anything to avoid his fall because everything was very fast,” he said in a police interview.

Evidence from investigators found the snow was hard and icy, which made it difficult to ski - despite Mr Drigo claiming it was “powdery”.

Patrols from the resort - who were called to help an unconscious Mr Choi - later pointed out the difficulty these conditions pose to police.

The inquest heard although the corridor is “not considered extreme, it is nevertheless reserved for experienced skiers” and “many falls” had taken place on the slope that morning.

"The accident could have been avoided if the ski instructor had correctly assessed their ability..."

One couple, Helen and Roger Hughes, quit the group Mr Choi had been in because they felt it was “too extreme” for them.

“In my opinion, the accident could have been avoided if the ski instructor had correctly assessed their ability,” Mrs Hughes said.

Mr Hughes added: “Philippe never asked if we were OK and if we were happy to carry on. As such I decided to leave the group and decided the site he was taking us on was too dangerous."

The inquest also heard how low cloud and poor weather conditions had impacted the ability of skiers to assess the surroundings.

A toxicology report detected no drugs or alcohol in Mr Choi’s system that could have impacted his senses or judgement. There were also no defects with his equipment.

Assistant coroner Ms Hayes told how Mr Choi had an “inadequate introduction to off-piste skiing”.

“I am satisfied it would not be sufficient to say that it was simply an accident,” she concluded.

“We have heard from Mrs Hughes that this accident was avoidable.

“I am satisfied that on the expert evidence given to the French public prosecutor, they held a manslaughter charge in this case.”

She agreed with the French courts that Mr Choi’s death was caused by gross negligence. It was not revealed what penalty Mr Drigo faced.

‘He was such a lovely man’

Mr Choi was a highly respected doctor and the lead urology surgeon for renal cancer in the East Kent Hospitals Trust.

He was vice-chairman for the Renal Cancer Service and the chairman of Laparoscopic Urological Surgery for the Kent Cancer Network.

He was appointed consultant at William Harvey Hospital in Ashford and subsequently developed laparoscopic renal surgery in east Kent.

Popular with both staff and patients, he was also respected as a teacher and trainer.

He was hit by heartbreak when he lost his wife, Debbie, to breast cancer 12 years ago.

After his death in 2016, Mr Choi’s partner Abbey described him as “such a lovely man who would help anyone”.

Speaking of the tragedy, she said: “Bill was a very experienced skier and always wore a helmet and didn’t take risks.

“We were in different groups and I just got a phone call asking me to return to the hotel because Bill had a fall.

“My first thought was that he might have broken a leg, but he died. It is devastating, particularly for the boys, whose mother Debbie died.”