Faith schools will no longer be allowed to redact questions about evolution and reproduction from science exam papers, and any attempt to do so will be treated as “malpractice” the exams regulator has said.

Ofqual has written to exam boards saying that any agreements between exam boards and schools which allow censorship of questions “must not be made” because the practice left exam papers incomplete and “unfit for purpose”.

Schools found to be involved in the censorship of exam papers would be subject to sanctions such as the withholding of results or refusal to provide future exams, it said.

Director of regulatory operations, Jane Farleigh, wrote: “Agreements that allow redaction, in any form, to take place must not be made between awarding organisations and centres. Any agreements that are currently in place should be withdrawn before any further assessments are taken.”

The letter came following criticism from secularist campaigners that boards who allowed the practice were accommodating creationism in science lessons.

The most high profile known case of schools redacting exam questions that run counter to their faith is that of Yesodey Hatorah Senior Girls’ school, a Jewish School in Hackney, east London, although a number of other schools are believed to have done the same.

OCR, the board involved, had previously said the most reasonable approach was to “come to an agreement” with schools out of need to respect religious beliefs.

But today, it also published a statement clarifying its position, saying: “We have now been able to consider our position and have concluded that as a matter of policy schools should not be permitted to tamper with question papers prior to a student sitting an exam.”

A spokeswoman for Ofqual added: “Having looked into the issue, we concluded that while the practice was very rare, it should not be allowed.  Denying learners access to all the questions on a paper prevents the candidate achieving their full potential and therefore disadvantages them. It also threatens the validity of the qualification.  

“If awarding organisations suspect that schools or centres are redacting exam papers in the future we would expect them to act in the same way as they would for any other case of malpractice.”

Richy Thompson, faith schools campaigner at the British Humanist Association, which has campaigned on the issue, said: “Every child has a human right to scientific knowledge and evolution is fundamental to understanding how life came to be.

“This change of policy represents a victory of common sense over ignorance, and we will continue to work with the Government and Ofqual to ensure that no pupil is denied such vital information.”

Stephen Evans, campaigns manager at the National Secular Society, said: “This is a significant victory for the rights of children and young people to not have their education impeded by religious organisations seeking to pursue their own agenda of inculcation or indoctrination.”

Nobody from the National Association of Orthodox Jewish Schools, of which Yesodey Hatorah Senior Girls’ School is a member, was available to comment at the time of publication.