A “major concern” has been raised by Ofsted at the number of independent schools that are failing to carry out proper background checks on staff.

About a third of the private schools inspected by Ofsted failed to comply with new safeguarding regulations, the chief inspector’s report has revealed. Ofsted inspects non-association independent schools, those which are not members of the Independent Schools Council.

It found that around one in three did not meet the safeguarding rules because staff had not received up-to-date training on child protection, and safeguarding policies lacked detail, or checks on staff were not sufficiently rigorous.

The high figure compares to just 1 per cent of state schools that were found not to have complied with the safeguarding rules.

Christine Gilbert, the chief inspector, described the finding as “a major concern”. Miriam Rosen, Ofsted’s director of education, said some schools did not know the rules had changed and were failing to keep proper records.

The overall performance of the independent schools inspected by Ofsted showed that 57 per cent were good or outstanding, with 6 per cent of the 433 schools inspected judged as inadequate.

Pupil behaviour is good or outstanding in 81 per cent of the schools, which inspectors said was the result of clear and effective rules. Private faith schools improved their performance compared with previous years, with almost all developing pupils’ appreciation of other cultures as well as their own.

Muslim schools performed well, with all but one of the 52 inspected being judged as at least satisfactory. Half were described as good or outstanding.

But about a third of the 21 orthodox Jewish schools provided a narrow curriculum outside of religious education, Ms Gilbert said.