- 21 schools reportedly being investigated, some over radicalisation fears
- Concern that pupils are being taught 'narrow Islamic-focused curriculums'
- Inspectors reportedly found schools which haven't registered teaching hate-filled, misogynistic, homophobic and anti-Semitic material to children
Shadow education secretary Lucy Powell (pictured) said ministers needed to take immediate action to deal with the issue of radicalisation, claiming pupils at unregistered schools 'could be in harm's way'
At least 21 schools that haven't been officially registered in Britain are being investigated over fears some of them are radicalising pupils with 'narrow Islamic-focused curriculums', it has been claimed.
Education chiefs are said to be probing a host of 'illegal' schools across the country, a number of which are allegedly teaching hate-filled, misogynistic, homophobic and anti-Semitic material to children.
Shadow education secretary Lucy Powell said ministers needed to take immediate action to deal with the issue, claiming children at unregistered schools 'could be in harm's way'.
The Labour MP told The Sun: 'Despite warning after warning, they [ministers] have dragged their feet, leaving children in unregistered schools where they could be in harm's way.
'It is extremely worrying that Ofsted remains concerned that the number of children being educated in unregistered provision far exceeds the number currently known by the Government.'
The newspaper reported that at least 21 schools are currently under investigation with inspectors apparently finding a number of cases of children being taught 'narrow Islamic-focused curriculums'.
It is unclear exactly how many pupils are being taught at the 'illegal' schools, but experts say each unregistered institution tends to have fewer than 100 - particularly because some schools are based out of small religious centres or even people's homes.
The Department for Education said there would be 'no single knockout blow against those who seek to corrupt young people' but confirmed it was taking action to protect children from 'illegal' schools.
A spokesman added: 'We are taking unprecedented and direct action across the board to protect children, inform parents and support teachers, putting us firmly on the front foot.'
It comes after Prime Minister David Cameron vowed to 'shut down' schools which were 'filling children's heads with poison and hearts with hate' in his Tory conference speech last October.
Vowing to stand up to 'passive tolerance' which leaves children vulnerable to extremists, Mr Cameron announced inspectors would shut down Islamic religious schools promoting hate.
He also said some mosques in Britain were promoting hate and vowed to shut them down. In his Conservative conference speech, he said: 'Let me be clear: there is nothing wrong with children learning about their faith, whether it's at Madrassas, Sunday Schools or Jewish Yeshivas.
'But in some Madrassas we've got children being taught that they shouldn't mix with people of other religions; being beaten; swallowing conspiracy theories about Jewish people.
'These children should be having their minds opened, their horizons broadened - not having their heads filled with poison and their hearts filled with hate.
'So I can announce this: If an institution is teaching children intensively, then whatever its religion, we will, like any other school, make it register so it can be inspected.
'And be in no doubt: if you are teaching intolerance, we will shut you down.'
Two months after his warning, Ofsted set up a special task force to uncover unregistered schools operation outside of English laws.
The schools regulator said it had already uncovered unregistered Muslim faith schools which keep pupils in squalid conditions and teach a 'narrow' Islamic curriculum and said they pose 'a serious and growing threat' to the safety of hundreds of children, who may be vulnerable to extremism.
In December, inspectors shut down three unregistered schools in Birmingham, with one using 'anti-Semitic, homophobic and misogynistic material'.
Conditions in one were described as 'unhygienic and filthy'. A total of 94 pupils were being taught by adults who had not been suitably checked for work with children.
Ofsted has already found 15 such 'hidden' schools in the past year, running full timetables and involving about 800 pupils.
It is understood a large number of them catered for Muslim communities, but there were also schools of other faiths.
There are fears the true scale of Britain's secret schools could surpass that of the Trojan Horse scandal – in which state schools were infiltrated by hardline Islamists – as inspectors may have uncovered only the 'tip of the iceberg'.