A medic who worked in Oxford went berserk on a yachting holiday hosted by his best man, a disciplinary hearing was told today.

Radiographer Ian Johnson's behaviour spiralled out of control while he was a guest on board a yacht off Padstow, in Cornwall, the Health Professions Council fitness-to-practice hearing was told.

Mr Johnson, who was going through a divorce, drank cider for breakfast before he allegedly grabbed a young woman between the legs.

Mr Johnson then launched into a tirade of verbal abuse and vandalised the boat, before disappearing ashore in May 2005, the hearing in London was told.

Giving evidence, witness Andrew Carnegie said he had invited Mr Johnson, because he was worried about him. They had met while serving in the Royal Army Medical Corps.

He said: "I was quite concerned for his welfare. He had been having a lot of problems in his personal life with his divorce and was drinking heavily."

Mr Carnegie described how, during an evening get-together on board, Mr Johnson had "all of a sudden reached over and grabbed" a young woman sitting next to him.

He added: "I was shocked - there was no reason for it. In the time I have known Ian, it's not something I would have expected from him at all."

Mr Johnson, who was not at the hearing, denies all the allegations.