Stock photo. The school is facing a 'civil war' against LGBT students.

Materials calling for gay people to be put to death have been found in schools operating across the UK, according to the country’s most senior schools inspector.

Amanda Spielman, the chief inspector of schools watchdog Ofsted, made the claim Wednesday in a letter to the UK Parliament’s Public Accounts Committee.

In the letter, Spielman calls for new powers to tackle illegal unregistered schools, which operate without permission and often teach a narrow, fundamentalist faith-based curriculum.

She said: “My inspectors have been shocked by what they have found in these schools (…) in some schools we see extremely worrying material.

Spielman explained: “We have, for instance, found books that say it is acceptable for men to use physical violence against their wives, texts that say it is unacceptable for women to refuse sex to their husbands and literature calling for the death of gay people.

“These texts have no place in young people’s education.”

Spielman said: “This material has been found in poorly performing registered independent schools and even in a maintained community school, but also in unregistered schools, where our powers to tackle it are far more limited.”

She explained that Ofsted’s “current lack of powers to seize evidence means that we are tackling this problem with one hand tied behind our back.”

The schools inspector’s letter adds that “the number of children disappearing from the formal system and into unregulated, unregistered provision (…) is perhaps my greatest concern as chief inspector.”

It is a crime in the UK to operate an unregistered school.

In 2016, Ofsted launched a probe into unregistered schools operated in London by ultra-Orthodox Jewish groups.

As many as 20 illegal Charedi schools were thought to be in operation across the capital, many of which are registered as religious charities.

Several faith schools have also faced punishment for anti-LGBT+ teachings.

An investigation in 2014 found that Christian faith schools were using textbooks developed by US evangelicals, teaching that homosexuality is a choice, evolution is a lie, abortion is wrong, and HIV/AIDS can be avoided by following the bible.

A group of private Christian schools threatened legal action in 2016 after having their status downgraded by education watchdog Ofsted, partly for failing to “promote respect” for LGBT+ people and British values.

Elsewhere in the letter, the chief inspector warned about the “undue influence” of outside groups advocating “for changes in school policy on the basis of religion or culture” in schools across the UK, which “can lead to the curtailing of rights of other protected groups.”