A strictly Orthodox girls’ school accused of censoring science questions in a GCSE paper this summer insists that it is complying with exam regulations.

The Oxford, Cambridge and RSA Board (OCR) confirmed this week that it had found that part of an exam paper had been “obscured” by the Yesodey Hatorah Senior Girls’ High School in Hackney, north-east London.

A spokesman for the board, which launched an investigation into the school after a complaint made by the National Secular Society, stated: “We do not consider obscuring aspects of question papers to be good exam practice”.

Yesodey Hatorah this week denied media reports suggesting that the problematic topic had been evolution. Asked if the question concerned had been about human reproduction, the school’s principal, Rabbi Avraham Pinter, said: “It might be”.

Rabbi Pinter believed that the question may have been “covered up” rather than blacked out. But he added: “What we have done is standard practice among all Charedi schools.”

In previous years, he said, the school had sent a covering letter to the exam board after the exam to explain if a question had been omitted — but this had not been done this summer.

But he emphasised: “We have agreed guidelines with OCR, which allows us to respect the religious sensitivities of our parents, at the same time satisfy the requirements of the exam board.”

He pointed out that 78 per cent of girls at the school had passed the particular science exam at grades A* to C.

Yesodey Hatorah has traditionally been one of the highest performing Jewish schools at GCSE.

OCR, its spokesman said, was now “in the process of agreeing safeguards… to ensure good exam practice in the context of today’s pluralistic society”.

But the board has not revealed whether it has asked the school not to cover up questions in future. It stressed that its job was not to issue orders to the school. Rather, its role was “to ensure the integrity of its exams, and that’s what it is in the process of agreeing with the school,” the spokesman said.

The exam board has also raised the issue with the Department for Education, the inspection service Ofsted and other exam bodies.