The CBI on Thursday arrested Ashis Kumar Pandey, a house staff with RG Kar Medical College and Hospital, for his alleged role in the financial irregularities at the facility.

Pandey, some junior doctors said, was a leader of the Trinamool Congress Chhatra Parishad unit at the hospital and a close aide of Sandip Ghosh, the hospital’s former principal.

On Thursday, the CBI summoned Pandey, a resident of Howrah, to its office at Nizam Palace and began questioning him from 11am. He was arrested late in the evening.

Ghosh was the first to be arrested in the case of alleged financial irregularities at the medical college and hospital.

The CBI arrested him on September 2. Later he was arrested in the case of rape and murder of the junior doctor at the hospital.

Besides Ghosh, the CBI arrested three others for their alleged roles in the financial irregularities. They include Afsar Ali, Ghosh’s additional security guard; Biplab Singha, who supplied medicines and other items to the hospital; and Suman Hazra, who allegedly supplied medicines and medical equipment to the hospital at inflated rates.

Pandey is the fifth person to be arrested in this case.

The CBI did not issue a formal release on the arrest.

Sources said there were reasons to believe Pandey was part of a team that is primarily responsible for the financial irregularities at RG Kar.

“We will produce him before the special CBI court in Alipore on Friday,” a senior officer said.

A section of junior doctors at RG Kar alleged Pandey was part of a group responsible for instilling “threat culture” at the institution.

The disciplinary committee of the medical college and hospital summoned him on September 25 and recorded his statements.