NTA Chief, Abhishek Singh has defended the decision to cancel the NEET examination, saying the agency followed a strict zero-tolerance policy against irregularities. According to the NTA chief, a whistleblower report received on May 7 triggered an internal investigation, which found that some exam questions had circulated before the May 3 examination. He said the probe confirmed that a few individuals had prior access to the paper, prompting the cancellation of the exam and a CBI inquiry to protect the interests of over 22 lakh honest students.