Only one of 17 Jewish institutions that were suspected of being unregistered schools is currently under investigation by Ofsted.

Most of the others remain beyond further scrutiny by the inspection service because of what it regards as a loophole in the law.

The figures were presented in a witness statement to the Independent Inquiry into Child Sexual Abuse by Sophie Young, Ofsted’s principal officer for independent and unregistered schools.

According to her disclosure, Ofsted has visited 314 institutions suspected of being illegal schools of which 31 were religious.

Of the 17 Jewish institutions, one had closed, two were teaching pupils outside compulsory school age and seven had a “restricted” religious curriculum, which in effect put them out of Ofsted’s reach; in four other cases, there was insufficient evidence to suggest they were operating illegally and in the remaining two, insufficient evidence along with a restricted curriculum.

Ofsted has repeatedly voiced frustration at its lack of power to scrutinise unregistered institutions and in her own evidence to the IICSA its chief inspector Amanda Spielman detailed concerns about safeguarding within them.

It is illegal to run a school teaching children of 16 or under for more than 18 hours a week without registering with the Department for Education.

But under the current law, an institution offering a narrow curriculum, such as only religious studies, falls outside the definition of a school.

Earlier this year, the government launched a consultation to tighten the law but it has been suspended because of the coronavirus outbreak, Mrs Spielman told the IICSA.