A model-turned-history teacher at a prestigious South African boarding school has resigned amid claims she had a sexual relationship with at least one pupil.
Fiona Viotti, 30, who married just last year, quit £16,000-per-year Bishops Diocesan College in Cape Town last Thursday before an 18-year-old student came forward to say he was in an 'intense' sexual relationship with her.
The boy claims he entered into a consensual relationship with Viotti, who coached the water polo and under-14 rugby team, but when he tried to end the relationship she became controlling, at which point he told his parents who called in a lawyer.
Officials at the elite school have now brought in their own lawyer to probe claims that Viotti, niece of former South African national rugby coach Nick Mallet, had a string of affairs at the school going back six years.
It is understood that investigators are preparing to interview 40 current and former pupils about the allegations.
Fiona Viotti, 30, has quit a prestigious South African boarding school where she taught history after an 18-year-old pupil said he had an 'intense' sexual relationship with her
Officials at the £16,000-per-year school now believe that several boys were involved in relationship with the teacher over a number of years, and have called in lawyers to investigate
It is thought that a number of explicit videos featuring Viotti performing sex acts have been shared among the boys, and have been posted online.
Lawyers for Viotti have warned that the content was posted without her permission and sharing it is illegal.
Local reports do not make it clear how many of the boys are thought to have been directly involved in relationships with Viotti.
It is also not clear if any of the boys were being taught or coached directly by Viotti, or how long her alleged relationship with the 18-year-old pupil was.
The school said in a statement that they are probing an allegation of 'serious misconduct' by a former teacher, and there is reason to believe that several boys 'have been affected over a number of years.'
Viotti's lawyer has spoken only to deny claims that she had fled the country, though said she is 'stressed' over the allegations. No charges have yet been laid, he added.
A school newsletter reveals that Fiona only married 13 months ago, to Pavo Viotti, 32, who has a top venture capital and private equity company in Cape Town.
The pair have now separated, according to local reports.
Outlining the claims against Fiona, one of the boy's parents told the IOL news site: 'He was a willing participant in the beginning but became a victim when he couldn't get out of it.
'The teacher started texting him to come to her house on the campus and that's how it started but it got to the stage where he had had enough.
Viotti - the niece of former South Africa rugby coach Nick Mallett - was a history teacher, but also coached the water polo team (pictured) and the under-14 rugby team. It is not clear if any of the alleged victims were taught or coached directly by her
The former model had been dating banker Pavo Viotti (right) since 2008 and the pair married just 13 months ago
Pavo is now said to have separated from his wife, and refused to answer the door at their £350,000 Cape Town property. She is thought to be living with her parents
'But the teacher wouldn't let him go and he went to his parents for help and they went to the headmaster and now it is all coming out.'
Sources told local media: 'It seems this has been going on for about six years.
'That is why the headmaster is asking for other boys past and present to come forward with information. If the rumours at the school are correct there could be many many more involved.'
The South African Police Service have not been involved as criminal charges have not been laid as the schoolboy is two years over the age of consent.
A school source