“Photographs of her modeling were taken by a professional photographer who also teaches photography part-time at the $45,000-a-year private school. These pictures were stolen and passed on to some pupils at the school without the agreement of the photographer, who holds the copyright. The matter is being investigated.”

The pictures were taken by Fiona Corthine, within the grounds of the school where she and Miss Salley both live, in what a school spokeswoman suggested was an “art project.” She said the pictures were stolen by a pupil, who is thought to have found them on a memory stick in the photography laboratory.

The school spokeswoman dismissed as “hearsay” reports that the majority of the school’s pupils, teachers and kitchen staff had seen the photos. She also said reports that Miss Salley had left the school in a flood of tears were “definitely not true,” adding: “She hasn’t left the school. She’s a very good art teacher.”

She was unable to confirm Miss Salley’s whereabouts today, adding: “They’re on end-of-term timetable. I have no idea whether she is teaching or not – she may not have had any classes in her timetable but if she’s supposed to teach, she’s probably teaching.”

The sensational pictures, including a shot of the teacher draped over a bookcase crammed with tomes on art history, have been circulating the classrooms, dorms and corridors of Harrow. Her tousled brunette hair reaches down to the small of her tanned back. In another moody image, she stares straight at the camera. The pictures were captured by Miss Corthine, as first reported by the Daily Mail’s Richard Kay.

They are believed to have been taken on school grounds – in its art rooms. The pictures were discovered by a pupil in the school’s photography laboratory – where they had been left on a memory stick.  To the horror of Miss Salley –a former Miss Northern Ireland who used to go out with England rugby star Matt Dawson – the pictures circulated like wildfire on pupils’ mobiles. They have been seen by the majority of the school’s 825 male pupils, its teachers and even its kitchen staff. Pupils who forwarded these pictures to the Mail did so after censoring them with modesty boxes.

The images have even made it as far as Miss Salley’s former school – Merchant Taylors’. Pupils first started to receive the pictures – on their iPhones and BlackBerries – last weekend.  Harrow staff, noticing a stir, were made aware of the scandal on Tuesday. They have since demanded that all pupils delete the pictures. Any pupil caught circulating them has been threatened with immediate suspension.

Sources at the school said humiliated Miss Salley, a former Cambridge University student, fled the school in tears and was not expected to return. Pupils have been told she fears her reputation has been so damaged, she will never teach again. ‘She was already the subject of hundreds of schoolboy crushes so naturally the photos went round the school like wildfire’, said a source.

This is not the first time Miss Salley has attracted unwanted attention to the school. She revealed in 2006 that she had received advances from one of the pupils. ‘One of the boys kept sending me love letters…another pupil used to turn up to my classes even though I didn’t teach him,’ she said.

Miss Salley has taught at the school for several years, but took a career break a few years ago to work for Comic Relief does Fame Academy and as a researcher for the BBC’s Hard Sell. Prior to her teaching career, she co-hosted The Big Breakfast with Johnny Vaughan on Channel Four and also starred in an ad for the Peugeot 106. The trained ballet dancer dated Mr Dawson for six years before the couple split in 2008.

Miss Salley was unavailable for comment. Harrow was founded in 1572 under a Royal Charter sanctioned by Elizabeth I. Two kings and seven prime ministers attended the school, including Winston Churchill.