The chaplain of a top private school has been found guilty of molesting a pupil who he plied with wine and oysters while discussing the arts and teaching him how to be “posh”.

As part of his advice on etiquette, Gary Dobbie urged the young teenage boy to sleep naked and wear silk boxer shorts because that was what “posh people” did.

The 67-year-old stood trial after denying four counts of indecent assault against the boy between 1986 and 1991 while he was teacher and chaplain at Christ’s Hospital School in Horsham, West Sussex.

On Friday a jury at Hove Crown Court returned the majority verdicts on all charges after deliberating for just over six hours.

Dobbie – who has been remanded in custody after last year being convicted of abusing eight other pupils – will be sentenced next month for all the offences.

He is one of five ex-teachers convicted after police investigated complaints spanning 30 years by 22 of the school’s former students.

In the latest trial, Dobbie’s victim told jurors it was “habitual” for him to be groped during night visits to his on-site lodgings while he was given wine and once fed smoked oysters.

Dobbie preferred to smoke cigars but would buy Turkish cigarettes for his pupil and also assaulted the boy during two school trips – at one point drunkenly lunging at him in a violent and sexual manner.

Describing him as “a very civilised man” who loved indulging in the grandeur of high church traditions, the man said the whole school would attend Dobbie’s services in the chapel four or five times a week.

He told how visiting Dobbie was an “escape” from being bullied. But he was shown little sympathy and instead groped under his school shirt while they sat alone on a sofa.

The man said: “(While he was doing this) he was talking about philosophy, art or classical music.

“It happened many, many times, easily into three figures.”

Gary Dobbie court case
Christ’s Hospital School headmaster Simon Reid said in a statement that he was ‘deeply sorry’ that victims were not protected (Christ’s Hospital School/PA)

As a “real treat” they watched Inspector Morse together on television in a darkened room while drinking red wine and eating spaghetti carbonara as similar assaults were carried out.

The man said due to his “poor background” he was in awe of such luxuries, adding: “It was the first time in my life I had heard of smoked oysters, let alone seen one.

“I desperately wanted to be posh.”

The married father – who still battles with urges to suppress the traumatic memories – said when he confided in a fellow teacher at the school he was told to “get over it and move on”.

Dobbie and other single male house masters would organise parties where champagne was served and the best-looking boys were picked to be waiters, he said. They were allowed to drink and smoke – even though this was banned for pupils on school premises – but had to serve the teachers while wearing cycling shorts.

Dobbie was arrested while teaching at independent Shrewsbury School, Shropshire, where he worked after leaving Christ’s Hospital. He then moved to France after living in Hereford.

He was found guilty last year of 15 charges detailing multiple offences against six boys and two girls as young as 12 between 1998 and 2001. He had denied 12 counts of indecently assaulting four boys and two girls, attempting to indecently assault a boy and two counts of indecency with a child.

Sports coach Ajaz Karim, was jailed in August for 10 years after assaulting six girls between 1985 and 1993.

In July, James Husband – also known by his middle name of Andrew – was jailed for 17 years for raping and indecently assaulting a girl as young as 14 between 1990 and 1994.

Peter Webb and Peter Burr admitted indecently assaulting pupils at the school between the 1960s and 1980s and were also jailed.

Christ’s Hospital is one of the oldest boarding schools in the country, dating back to the 16th century, and the Queen is a patron. Pupils still wear a Tudor-style uniform of a long blue coat and high yellow socks with boarders charged fees of up to £31,500 a year. Poet Samuel Taylor Coleridge and Sir Barnes Wallis, inventor of the bouncing bomb, are counted among its famous alumni.

In a statement, headmaster Simon Reid said it was a “very dark period” in the school’s history and he was “deeply sorry” that victims were not protected.

He added: “I am conscious that it may not provide much consolation to those whose lives have been blighted in this way, but the school today is a very different place, one in which the safety, happiness and wellbeing of our pupils is at the centre of all we do.

“The close links with local statutory agencies help ensure that our practices and decision-making are both compliant, effective and open.”