The Central Bureau of Investigation on Sunday said it has filed a first information report about alleged irregularities in the National Eligibility-Cum-Entrance Test held on May 5.

The agency filed the case based on a complaint by the director of the Department of Higher Education in the Union Education Ministry. The complaint alleged that “certain isolated incidents occurred in a few States” during the NEET examination, which is conducted for admission to undergraduate medical courses.

“Special teams have been formed by the CBI to investigate the matter on top priority,” the agency said in a press release. “Special CBI teams are being sent to Patna and Godhra where local police cases have been registered.”

The Centre, while announcing on Saturday that the matter would be handed over to the CBI, also set up a high-level expert committee “to ensure transparent, smooth and fair conduct of examinations through National Testing Agency”.

The committee has been tasked with recommending reforms in examination processes, improving data security protocols and reviewing the structure and functioning of the National Testing Agency, which conducts the NEET exam.

The results of the entrance examination were announced on June 4. Subsequently, several aspirants alleged that an inflation of marks had led to 67 candidates securing the top rank, including six from the same examination centre.

Some reports also alleged that at some centres, the question paper was leaked before the examination.

On June 18, the Supreme Court told the Union government and the National Testing Agency that even “0.001% negligence” in conducting the NEET examination should be looked into with all seriousness considering the immense labour put in by the candidates.

The Centre on June 13 told the court that grace marks awarded to 1,563 candidates in the test would be cancelled. They would be given the option to either appear for a re-examination or retain their original scores, which would exclude the compensatory marks that had been given to them earlier, the government had said.

The re-examination for these candidates was held on Sunday. Out of the 1,563 candidates eligible to retake the test, 813 students (52.01%) appeared, while 750 (47.98%) did not turn up, NDTV reported.

The National Testing Agency had opened seven exam centres for the retest in Chhattisgarh, Gujarat, Haryana, Meghalaya, and Chandigarh.

Amid the allegations about irregularities in the NEET undergraduate examination, the Union health ministry on Saturday postponed the NEET examination for admissions to post-graduate medical courses in the country, also known as the NEET-PG exam.

The ministry said the exam was cancelled “in the best interests of the students and to maintain the sanctity of the examination process”. It clarified that the rescheduled dates for the test would be announced after “a thorough assessment of the robustness of processes of NEET-PG Entrance Examination”.