The government and the National Testing Agency cancelled the NEET-UG examination and ordered a re-test after receiving information about possible irregularities in the question paper, sources said.
The decision affected nearly 23 lakh candidates who appeared for the examination held on May 5 across 551 cities in India and 14 overseas centres.
According to government sources, inputs regarding malpractice reached the NTA on the evening of May 7 and were escalated to central agencies the next morning for verification and investigation.
Within four days, the government and the NTA examined the matter, cancelled the examination, and referred the case to the Central Bureau of Investigation.
Government sources said the authorities chose to cancel the examination rather than risk disadvantaging students who had prepared honestly.
“The decision was costly for the government. It was the right decision for the student,” a source said.
Officials said action was taken within hours after it was discovered that some questions from the paper had allegedly been accessed by miscreants.
The government described the re-test as the fairer option despite the logistical difficulty involved.
Sources also said the CBI inquiry would determine how the alleged breach took place, including whether there were lapses within the NTA’s own processes.
The NTA has said gaps in confidential procedures would be addressed and that corrective work had already begun.
The CBI has arrested five people in connection with the case, including Mangilal Biwal, Vikas Biwal, and Dinesh Biwal from Jaipur, Yash Yadav from Gurugram, and Shubham Khairnar from Nashik.
Investigators have seized mobile phones, laptops, and other digital devices for forensic examination and are conducting searches at multiple locations.
CBI officials also visited the NTA headquarters to collect documents related to the examination and question officials involved in the process.