Dr Ghosh, along with two vendors, Biplav Singha, Suman Hazar, and the additional security to Dr Ghosh, Afsar Ali were arrested by the CBI.
The ex-principle is under investigation for alleged corruption and financial irregularities at the college and hospital, following a directive from a single bench of the Calcutta High Court, which directed the CBI to probe the matter.
The alleged financial irregularities at the state-run RG Kar hospital came under the scanner after the rape and murder of a doctor trainee in the seminar room of the state-run facility.
The CBI has accused the ex-principal of twisting the process for the recruitment of medical house staff at the hospital to appoint doctors of his choice. The central probe agency has also accused Ghosh of granting the hospital's contracts to his aides and thus violated rules.
On August 24, on orders of the Calcutta High Court, an official FIR was registered by the CBI against Ghosh in the alleged corruption case.