A once mild-mannered RAF sergeant transformed into a sex-obsessed shadow of his former self by road crash injuries has won a £1.7m compensation payout.

Robert Cornes' personality was so changed when he was struck down in a freak accident that he once even threatened one of his own female carers with a knife when she rejected his advances, London's High Court heard.

Formerly a highly-rated RAF aircraft engineer, his aggressive temper, foul language and "sexually inappropriate behaviour" mean even his loved ones have trouble coping with him.

Mr Cornes, 43, was walking along Corn Street, Witney, with his girlfriend on the night of July 19, 2002, when a car struck a bus shelter that collapsed on top of him.

The motorist involved - David Southwood, of Wood Green, Witney - was later jailed after pleading guilty at Oxford Crown Court to dangerous driving and drink driving.

Mr Cornes' barrister David Pittaway told the High Court he was now prey to "significant behavioural problems", including "increased aggression and sexual disinhibition".

The accident victim, who has since moved back to his childhood home in Newcastle-under-Lyme, Staffs, spent several weeks in intensive care after the accident and, although he has made a remarkable recovery from his physical injuries, he suffered grievous brain damage.

Mr Cornes, he added, will need to be looked after and supervised by a team of professionals for as long as he lives and his problems are such that his carers must all be male.

"He has suffered a substantial alteration in his personality," said Mr Pittaway, who added that, when he was taken off an anti-psychotic drug in 2006, the result was "increased aggression and sexual disinhibition" so that women carers "are no longer appropriate for him".

Also prey to "excessive alcohol intake and social isolation", the QC added: "The tragedy of it is that he does have insight into the loss of his career and social relationships".

Judge Richard Seymour QC said: "The reasons why Mr Cornes needs support are not really related to any inability on his part to care for himself in his own home, but rather to the fact that his personality has been altered."

The judge said that, without an extensive package of support, Mr Cornes would become "an isolated and lonley individual in the future".