The CBI on Friday arrested the principal and vice principal of a school in Jharkhand's Hazaribagh in connection with the NEET-UG paper leak case, officials said.

Ehsanul Haque, the principal of Oasis School, was made the city coordinator of Hazaribagh for the medical entrance exam conducted by the National Testing Agency (NTA) on May 5, they said.

Vice Principal Imtiaz Alam was designated as the NTA's observer and the centre coordinator at the Oasis School, officials said, adding the CBI is also questioning five more people from the district in connection with the paper leak case.

The federal probe agency arrested Haque and Alam after detailed questioning, they said.

Both the accused came under scanner during a probe by the Bihar Police's Economic Offences Unit (EOU) which was investigating the case earlier. The team had found burnt question papers of NEET-UG during a raid at a hideout of the solver gang, officials said.

In a statement, the EOU had claimed the "leaked" NEET-UG question paper was allegedly obtained from the Oasis School in Hazaribagh by the notorious Sanjeev Kumar alias Lutan Mukhiya gang.

It had said the investigators had matched a partially burnt question paper found from the Patna safe house with the reference question paper provided by the NTA, confirming the leak's origin.

However, it could not clearly establish who was behind the alleged paper leak, officials said.

According to them, the probe had also shown that laid down guidelines for opening the question paper boxes were not properly followed by the authorities in Hazaribagh.

In media interviews, Haque has maintained that the box carrying the question papers could not be opened because its digital lock, which was supposed to unlock automatically, had malfunctioned.

Following this, he contacted the NTA, which asked him to use a cutter to open the box, Haque has claimed.

The boxes carrying question papers have two locks -- a manual one that must be opened with a key and cutter and a digital lock that opens with a beep sound 45 minutes before the examination.

The CBI has registered six FIRs in the NEET-UG paper leak case which included its own FIR on a reference from the Union Education Ministry and five from the states where it took over investigation. The probe agency has taken over one case each in Bihar and Gujarat and three cases in Rajasthan.

On Thursday, CBI made its first arrests in the NEET-UG paper leak case, taking two people in custody in Patna while three candidates in Gujarat who had allegedly solicited help to clear the exam recorded their statements with the probe agency.

NEET-UG is conducted by NTA for admissions to MBBS, BDS, AYUSH and other related courses in government and private institutions across the country. This year's exam was conducted on May 5 at 4,750 centres in 571 cities, including 14 abroad. Over 23 lakh candidates appeared for the test.

The first CBI FIR was registered on Sunday, a day after the ministry announced it would hand over the probe into the alleged irregularities in the conduct of the exam to the central agency.

The demand for a CBI probe was raised by a section of protesting students.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.