The Exclusive Brethren is being investigated by HMRC over funding practices relating to its faith schools.

According to a report in The Times, the group, also known as the Plymouth Brethren, operate 34 schools at an annual cost of £30 million. Though a spokesman confirmed that Brethren schools follow the national curriculum and the website says "emphasis on religion at school is minimal," The Times cites allegations that children are segregated by gender, and certain books, including JD Salinger's Catcher in the Rye, are banned.

HMRC is now investigating tax rebate claims on parental donations to one of the schools. The Brethren receives millions of pounds of charitable tax relief each year, but up to £4 million of that could now be at risk if HMRC uncovers any malpractice.

A spokesperson for the Brethren told Christian Today that the school is among other faith schools also being investigated over gift aid. "The Plymouth Brethren Christian Church (PBCC) supports the government's right to levy taxes and do not in any way evade tax," a statement from the church said.

"The tax treatment of funds contributed by parents to charitable schools is far from straightforward, and a number of faith group schools and schools run by charitable foundations are subject to an ongoing review by HMRC. During this review we have sought the very best financial and legal advice and continue to cooperate fully with HMRC."

In an earlier article, The Times refers to Brethren's disciplinary practices, claiming that any member who breaches the group's rules risks being ostracised and thrown out, a process known as "shutting up" and "withdrawing from".

"If a Brethren member is shut up, no one except local elders can talk to them. Children move out of the homes of shut-up parents to live with other members of the community, often for months. If breaches continue, the shut-up member is withdrawn from. Under this ultimate sanction, it is often found that nobody in the sect will speak to that member again," The Times reports.

A statement on the Brethren's website refutes many of the claims made in this article, including a comment by Kevin Rudd, the former prime minister of Australia, who condemned the group as an "extremist cult" which "breaks up families".

"The PBCC is a mainstream Christian church," the statement maintains, adding that Brethren life is not "restricted and controlled" as the article suggests, but "PBCC members find their lives to be full, varied and rewarding."

It also highlights allegations that it mounted an "extraordinary lobbying campaign" to pressurise the Charity Commission into granting the church charitable status.

"BCC members support whatever Government is in power and make use of their democratic right to approach MPs or Peers about any issues of concern," the statement reads.

The church said in its statement to Christian Today: "The PBCC holds the same basic Christian truths as the Church of England, Roman Catholics, Methodists, Baptists and others. The PBCC is a group of observant Christians and are a mainstream Christian Church who choose to practice our faith fully in accordance with the Bible.

"We are not a 'cult', we are not secret and we have nothing to hide. Our meeting hall trusts have been recently investigated by the Charity Commission and our charitable status has been confirmed; all trust practices comply with their regulations."