Immediately after the question papers of the AIEEE were leaked, CBSE postponed the two exams which were scheduled to begin at 9:30 AM and 2:00 PM today, a senior HRD ministry official said here.
"Fresh set of questions were distributed to students", said CBSE chairman Vineet Joshi, adding, an enquiry will be conducted into the incident and those involved will be punished.
"When we got to know (about the leak) in the morning, our aim was to do it without causing much inconvenience to most of the children...first was to ensure the exam happens as early as possible and that we have been able to do," he said.
The exams for the 1st paper slated for 9.30 AM began at noon and the second paper to start at 2 PM was conducted at 4:00 PM.
AIEEE is held in two parts. While the first paper is for Bachelor of Engineering (B.E.) aspirants, the second paper is for students wanting to pursue Bachelor of Architecture (B.Arch).
About 12 lakh students across the country sat for the test at over 1,600 centres in more than 80 cities today.
UP Special Task Force's (STF) Senior Superintendent of Police Vijay Prakash said they received a copy of the question paper last night.
"We faxed the paper to the CBSE chairman and it was confirmed this morning that the paper was the original one," he told PTI.
This is for the first time that AIEEE was also held in the online format for students willing to appear in this mode, which was also postponed accordingly.
About one lakh candidates from 20 cities in India registered for the examination online.
AIEEE is conducted to gain admissions into National Institutes of Technology and other engineering colleges in the country.
Prakash said so far Bihar and Kanpur link have been traced and the STF was working on it.
Though sources said that at least four persons have been detained and raids were carried out, there was no official word on it from the authorities.
Special Director General of Police Brij Lal said in Lucknow that a police informer claimed that the leaked AIEEE papers were available for Rs 6 lakh each.
"Based on the information provided by the informer, STF is looking for the accused," he told reporters.
The leaked paper was recovered in Lucknow, Brij Lal said, adding that the STF was also looking for people arrested in the past in connection with paper leak cases.
The CBSE chairman said those students who are also appearing for the Armed Forces Medical College (AFMC) examination, being held today, will be allowed to appear for the AIEEE on May 8.
The May 8 exam will be held at the same centre and the same admit card will be valid.