The Central Board of Secondary Education on Wednesday said it will hold the Class 12 economics board exam and the Class 10 maths board exam again after reports that the question papers for the two subjects had leaked.

The news comes hours after Class 10 students sat for their maths exam on Wednesday. A handwritten version of the question paper had been circulated on WhatsApp on Tuesday, and many of the questions in that had appeared in the exam on Wednesday, NDTV reported.

The Class 12 economics exam was held on Monday. The board had denied any such question paper leak on social media and WhatsApp the same day.

The CBSE said it had made the decision “with the view to uphold the sanctity of the board examinations and in the interest of fairness to the students”.

The re-exams will be held at all centres because the CBSE set one set of question papers for all regions this year. The board said it will announce the dates of the re-examinations on its website within a week, but a few school principals told that they will most likely be held after the last board exam on April 12.

Before rescheduling the examinations, authorities also have to take into consideration several entrance exams that are coming up – the National Eligibility-cum-Entrance Test is on May 6; the written Joint Entrance Exam (Mains) for engineering is on April 8; and the JEE online test is on April 15 and April 16.

Human Resource Development Minister Prakash Javadekar said a police complaint had been lodged against the leak. “An investigation is under way, and strict action will be taken against those who are involved,” he said at a press conference. “We have also decided to tighten security when the papers are distributed.”

The joint commissioner of police (crime), special commissioner of police (crime) and the Delhi commissioner of police held a meeting on Wednesday evening to discuss the matter.

Javadekar said the leak was reported only from a few schools in Delhi, ANI. The Cabinet has given its approval for the National Testing Agency to come into effect from next year to ensure leak-proof examination, he added.

Meanwhile, a few parents and students may move the Delhi High Court over the paper leak. They have claimed that the Class 10 social studies question paper was also leaked on social media before the exam on March 22, and so was the Class 12 biology paper before the exam on Tuesday, according to The Times of India. There were similar rumours about the accounts and business studies question papers being leaked as well. However, the CBSE has dismissed these rumours.