A 30-YEAR-OLD maths teacher, Jeremy Forrest, at Bishop Bell Church of England School, Eastbourne, who fled to France with a 15-year-old pupil, after their relationship was discovered last September, was jailed for five-and-a- half years on Friday for child abduction and five counts of sexual activity with a child.

Mr Forrest, who is married, has also been banned for life from working, volunteering, or having unsupervised contact with children.

Judge Michael Lawson QC rejected Mr Forrest's defence that he had run away with the girl, who cannot be named, because she had threatened suicide if they were separated. He told Mr Forrest that he had chosen "to ignore the cardinal rule of teaching by never attempting to maintain proper boundaries between himself and the girl". He had subjected the family to "appalling distress".

In a victim-impact statement, the mother of the girl, who has now left the family home, said that she felt that the daughter she knew was "dead. . . It upsets me beyond words." The girl is understood to be close to Mr Forrest's family, and Sussex Police are investigating the possibility that, during Mr Forrest's trial, the two may have communicated through a third party.

After Mr Forrest was sentenced, the executive head teacher of Bishop Bell, Terry Boatwright, said that the school was saddened by the events that had led up to the trial, and their wider impact. "We remain deeply shocked by the actions of Mr Forrest, and his betrayal of the trust placed in him."

For many years, Bishop Bell - a former secondary modern school, built in the mid-1950s to serve one of the poorest areas of Eastbourne - was a troubled, unpopular school in challenging circumstances. Over the past decade, however, it has become one of the most sought-after, successful schools in East Sussex. It is unique in England as having improved examination results consecutively over 14 years. It is currently helping to improve six other schools.

Nevertheless, it has been involved in three scandals in as many years. In 2009, a temporary supply teacher, Robert Healy, who had occasionally covered lessons there, was convicted of child-abuse. Last year, the long-term chairman of governors, Canon Gordon Rideout, who has since been unfrocked, was jailed for similar offences (News, 24 May).

Media accounts of Mr Forrest's case have queried safeguarding procedures at the school, asking whether more could have been done to prevent the inappropriate relationship. But Mr Boatwright, who is widely credited with turning round Bishop Bell since he took charge in 1996, firmly rejected suggestions that senior staff and governors had been too slow to act on rumours of wrongdoing.

His stance was backed this week by a safeguarding expert, Chris Mills, who told a BBC interviewer at the weekend that the school had acted properly and promptly.

Until last September, the school had had no evidence of a relationship between Forrest and the pupil, but had investigated and informed the local authority months earlier of "limited anecdotal hearsay", Mr Boatwright said. Moreover, even after investigating more serious concerns brought to their attention by another source, the police had handed the matter back to the school in early September.

The school had also acted promptly in the case of Mr Healy. When evidence of a possible relationship between Mr Healy and a pupil had emerged, it had been immediately reported to the police and local authority, and the school had been instrumental in bringing him to justice. Decisions made concerning Canon Rideout were appropriate, and in line with the view taken by the Independent Safeguarding Authority.

An OFSTED inspection in November, led by its senior safeguarding expert, found the school's procedures secure, and identified no weaknesses. Staff have already been given extra training, however, focusing on e-safety and the use of social media, and a new social-media policy has been introduced.

The events are now being scrutinised in the Serious Case Review being carried out by the local Safeguarding Children Board. "We are keen to act on any learning that comes out of the review," Mr Boatwright said.

Before joining the staff at Bishop Bell, Mr Forrest taught at Bishop Justus C of E comprehensive, in Croydon. A former Bishop Justus pupil, Chloe Queen, who was in his tutor group between the ages of 12 and 16, told the Daily Mail that he had singled her out for compliments and had invited her to hear his band play.

Miss Queen, who has now left school, said that he would hug her and "invade her personal space". Since Mr Forrest's conviction, "a string of girls" had told the Mail that they had witnessed "predatory behaviour", the newspaper said.