Ofsted inspectors have been given the go-ahead to use body-worn video cameras during inspections of suspected illegal schools.

The idea behind the pilot is to record evidence that the watchdog could use to secure more prosecutions against schools flouting the law.

All schools, whether state or independent, must register with the Department for Education, and are breaking the law if they do not.

The body which inspects educational establishments is calling for greater powers to inspect unregistered schools and says the current legislative framework is inadequate, with inspectors unable to seize evidence which hampers potential prosecutions.

Last month Hackney Council said "no real progress" has been made since it launched an unregistered educational settings strategy two years ago, aiming to ensure all schools in Hackney are registered. A lack of regulation framework was blamed along with the absence of central organisation with authority over yeshivas, which offer religious teaching to more than 1,500 boys within the Charedi orthodox Jewish community.

Ofsted has inspected more than 600 potentially illegal schools nationally, but only a few investigations have secured prosecutions.