The CBI has taken over the investigation of five new cases of alleged malpractices in the medical entrance exam NEET-UG that were being probed by police in Gujarat, Rajasthan and Bihar, officials said on Monday.

They said the central agency has re-registered one case each from Gujarat and Bihar and three cases from Rajasthan as its own FIR, while it is also likely to take up another case from Maharashtra's Latur.

Barring the case from Bihar, the other four appear to be isolated incidents of impersonation and cheating by local officials, invigilators and candidates, the officials said.

The CBI has already registered its own FIR in connection with the case on a reference from the Union education ministry to conduct a comprehensive probe, they said.

After taking over these new cases, the CBI is now probing a total of six cases pertaining to alleged irregularities in NEET-UG, the officials said.

NEET-UG is conducted by the National Testing Agency (NTA) for admissions to MBBS, BDS, AYUSH and other related courses in government and private institutions across the country.

The examination 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, a demand raised by a section of students protesting in several cities.

"The ministry of education has requested the CBI to conduct a comprehensive investigation into the entire gamut of alleged irregularities, including conspiracy, cheating, impersonation, breach of trust and destruction of evidence by candidates, institutes and middlemen," a CBI spokesperson said earlier.

The role of public servants, if any, connected with the conduct of the examination and also into the entire gamut of events and the larger conspiracy will also be under the scanner, officials have said.