England's exams watchdog has announced a review of rules allowing teachers to set question papers in the wake of allegations of exam leaks.
Teacher involvement in writing and reviewing exams has "many benefits" and malpractice is rare, but access to live exam materials, such as papers due to be taken by students, needs to be "appropriately controlled" and risks to security kept to a minimum, Ofqual said.
It said it will conduct a review of current rules and safeguards in place to stop confidential information being disclosed.
The move comes after two high-profile private schools became embroiled in a controversy over exam breaches.
Last week it emerged a senior staff member at Eton College had left the prestigious boys' school amid allegations he shared confidential information in relation to an upcoming Pre-U economics exam with other teachers.
Eton parted company with Mo Tanweer, head of economics and deputy headmaster of academics at the public school, after an investigation by the Cambridge International Examinations (CIE) exam board, it was reported.
In a statement, Ofqual said: "Ofqual will conduct a review of the rules under which serving teachers take part in writing and reviewing question papers, and the safeguards in place to prevent disclosure of confidential information.
"The involvement of serving teachers in the process of exam setting has many benefits and exam malpractice by teachers is rare.
"However, access to live materials must be appropriately controlled and risks to security minimised. We will investigate whether the safeguards in place are sufficiently robust and whether changes are needed."
A progress report will be published later in the year, the regulator said.
In a statement regarding Pre-U economics, Eton confirmed that a CIE investigation concluded there had been "a breach of exam security by one of Eton's teachers in relation to one of the Pre-U economics papers".
Eton added: "The teacher concerned has left the school. Whilst pupils had done nothing wrong, they were inadvertent recipients of confidential information and so the board awarded them assessed marks for that paper according to its established method."
In the case of Pre-U art history, Eton said that following a CIE investigation, pupils who took the qualification had been found to be "inadvertent recipients" of confidential information in relation to one paper, the Guardian reported.
This related to information that Eton pupils had been sent via a pupil at another school in advance of the exam, and no Eton staff member was involved.
Winchester College said it had treated the matter "with the utmost seriousness" and "greatly regrets what has happened".
"No boy was to blame for the exam irregularity, and the Board used standard procedures to award final grades," Winchester said.
"One teacher has retired from the school, and all those boys holding university offers dependent on a grade in art history have now had those offers confirmed by their first or second choice university."
It is understood that teachers can be involved in the process of setting exam papers for the qualifications that they teach.