Christian religious sect that runs 34 faith schools reportedly under investigation by HMRC over its funding practices

A religious sect that runs a string of faith schools where books are banned is reportedly under investigation by HMRC over its funding practices.

A report by The Times found that the Exclusive Brethren, a subset of the Christian evangelical movement, oversees 34 private schools that are financed through a network of Brethren-controlled charities.

According to the newspaper the Charity Commission made a deal with the sect to grant it charitable status, allowing it to secure tax relief worth up to £13 million a year. This decision was said to be made after pressure was heaped on the regulator's head, William Shawcross.

The schools, which cost £30 million a year to run, impose segregation of the sexes and are said to ban a host of novels deemed unsuitable for their pupils, including JD Salinger's Catcher in the Rye. They are also said to use textbooks in which passages about evolution have been removed.

These practices have been denied by the sect, which says it follows the national curriculum – however, it concedes that individual schools use their own discretion

HMRC is investigating whether the Exclusive Brethren wrongly claimed tax rebates on money donated to one of its schools by parents. If it is found to have done so, it could lose up to £4 million a year in tax relief across all its schools.

Sir Stephen Bubb, chief executive of Acevo, the UK charity leaders representative body, said the Charity Commission needed to explain why it had granted the Exclusive Brethren tax breaks in spite of evidence that the sect's practices are detrimental to the wellbeing of families.

"This is about the independence of the regulator," he said.

In 2011, the schools are also said to have introduced obligatory fees of £1,500 per year for their pupils that were subsequently recorded as voluntary contributions.

A Brethren spokesperson told The Times that gift aid had not been claimed on these sums.

"Such issues as there have been derive from uncertainty about the correct application of the rules," he said.

"Other faith schools are also currently being investigated by HMRC over gift aid."