Thousands of school teachers have had to be re-checked for criminal records - including if they are on the sex offenders' register - a BBC investigation has revealed.
William Gibson was cleared to work in schools (pic www.northnews.co.uk)
The vetting process began after Ofsted inspectors discovered serious flaws in the way most schools keep even the most basic of records.
Work has been taking place to re-check all staff where evidence clearing them to work with children has either been lost or never recorded.
It has cost taxpayers tens of thousands of pounds.
Despite a deadline of 1 April to complete the re-checking, the BBC can also reveal that some staff are still waiting to be cleared.
The BBC investigation focussed on 20 local authorities in the south of England.
It revealed schools in those areas could not prove that more than 3,500 teachers or school staff had been cleared by the Criminal Records Bureau (CRB).
It also found the schools could not prove that more than 8,000 teachers or school staff had been checked against List 99 - the government's own blacklist of people barred from working in schools.
Some local authorities could not provide figures for all the missing records in their area and many said they still had to complete the re-checking process.
Each repeated CRB check has cost schools £36 - leaving taxpayers living in the 20 local authorities with a bill of at least £130,000.
Re-checking List 99 is free, a Department for Education and Skills spokesperson (Dfes) said.
The local authority in Brighton said it still had to re-check more than 200 staff with the CRB, although a spokesperson added that all staff had been checked against List 99.
Southampton, Reading, Dorset, Portsmouth, Windsor and Maidenhead, Poole and West Sussex local authorities also confirmed retrospective checks were still being carried out.
THE 20 LOCAL AUTHORITIES
Isle of Wight
Windsor & Maidenhead
Wiltshire and Surrey local authorities said it was the responsibility of schools to make sure they had a central database in place, while Hampshire local authority refused to give any figures.
Only Bracknell Forest and Isle of Wight local authorities had no missing records, while Bournemouth and Wokingham were the only authorities to confirm they had filled in all gaps.
Margaret Morrissey, of the National Confederation of Parent Teacher Associations (NCPTA) said: "I am absolutely astounded that some local authorities still have not completed all the checks".
She said: "The bottom line is that if there is just one active paedophile [who had slipped through the net] then it is worth getting the checks sorted."
The Ofsted report was commissioned in January 2006 by the then education secretary, Ruth Kelly, amid a row over 88 sex offenders being cleared to work with children.
One of those was William Gibson, who began work at Portchester Boys School in Bournemouth early last year. The school found out he had a conviction for indecently assaulting a 15-year-old girl in 1980 and he was dismissed.
Ofsted inspectors looked at 58 schools and found "hardly any" took "even the simplest of measures in terms of record-keeping".
They found there was a culture of thinking it was "somebody else's job" and added that this could "compromise the way children are safeguarded".
Ms Morrissey added that she could not believe "after all the dialogue a year ago, the worry and upset it caused to parents, and the promises by Ruth Kelly, that local authorities will just assume schools are doing their checks".
Ofsted found "hardly any" record-keeping took place in schools
The Dfes would not comment on the fact some schools had not completed all the missing gaps in record-keeping.
A spokesperson said: "All maintained schools have a legal obligation to have their records up to date by 1 April. Dfes have sent out a number of reminders to this effect. Ofsted will be checking that records are up to date as part of their regular inspections."
The department did not know whether the re-checking had revealed anyone working in schools who should not have been.
"We would not know what would have happened in schools as a result of CRB checks either as part of this exercise in compiling the record or as part of the regular course of business," the spokesperson said.
"Schools were clear that the right checks did happen - the issue was that they did not have the comprehensive evidence to prove that. This is an exercise to sort out the records, so that schools will have the proper evidence."