Kolkata | The CBI on Friday summoned former principal of Kar Medical College Sandip Ghosh for the 14th consecutive day for questioning in connection with its probe into the alleged rape and murder of a postgraduate trainee doctor in the early hours of August 9.

Ghosh, officials said, has already been quizzed by the agency for over 140 hours.

Besides the gruesome crime, Ghosh is also under the agency's lens in the financial misconduct case at the hospital in which the sleuths have already registered an FIR against him and other entities.

Agency officials also searched and questioned the former principal at his residence last Sunday.

Ghosh was seen walking inside the CGO Complex in Salt Lake, which houses the agency's eastern regional headquarters, at around 10.45 am.

On Thursday, multiple CBI teams visited the state-run Kar hospital as part of its ongoing investigations.

The first of the three teams from the agency's Nizam Palace office probing the alleged financial irregularities reached the hospital morgue to inquire about its infrastructure, protocols involved in preserving dead bodies and conducting post-mortems, a CBI official said.

The five-member team spoke to hospital doctors and staff, including the head of forensic department and current vice principal, Dr Saptarshi Chatterjee, for further clarifications on the issues.

The probes followed complaints by the hospital's former Deputy Superintendent Akhtar Ali of trafficking of unclaimed bodies, among other allegations of financial misconduct like corruption in disposal of bio-medical waste, nepotism in floating construction tenders and so on, during Ghosh's tenure as principal.

A second CBI team from Nizam Palace simultaneously searched the hospital store building where medical and purchase records are kept, the official said.

Another CBI team on Thursday went to the chest department housed at the third floor of the hospital's emergency building where the victim was on duty that fateful night, inspected the crime scene and spoke to nurses and other hospital staff, it was learnt.

So far, the probe has resulted in only one arrest, that of Kolkata Police civic volunteer Sanjoy Roy, who currently remains in judicial custody.

With 18 days having passed since the CBI took over investigation charges on a Calcutta High Court order, several unanswered questions about the ghastly crime – such as whether multiple people were involved, DNA test results of the fluid found in the victim's genitals, forensic test reports of tissue samples found underneath the victim's nails, whether responsibilities have been fixed on the alleged alteration of the crime scene – still continue to dominate the public domain.

Calcutta High Court transferred the twin probe - into the August 9 rape-murder of the medic and allegations of corruption during the tenure of Ghosh - on August 13 and August 23 respectively to CBI.

Ghosh has been questioned by the central agency at its CGO complex office since August 16