Kolkata | CBI officers may conduct a polygraph test on Sandip Ghosh, the former principal of RG Kar Medical College and Hospital, where a woman doctor was allegedly raped and murdered earlier this month.

Ghosh, who resigned two days after her body was found in a seminar hall of the medical facility on August 9, has already appeared before sleuths of the central probe agency for questioning several times.

"We want to further verify Ghosh's answers, as there have been discrepancies in some of the replies to our questions. Therefore, we are mulling over the option to conduct a polygraph test on him," an official told PTI.

Ghosh was on Tuesday, too, grilled by investigators, as part of its probe into the rape-murder of the postgraduate trainee.

CBI officers have put forth various questions to Ghosh in the last few days, including specifying his role after getting the news of the doctor's death, who he had contacted thereafter and why he allegedly made the parents wait for nearly three hours before getting to see her body, the official said.

He has also been quizzed over the authorisation of renovation of rooms adjacent to the seminar hall of the RG Kar hospital, after her body was discovered there, he said.

The CBI had earlier obtained permission from a local court to conduct a polygraph test on Sanjay Roy, the civic volunteer who has been arrested for his alleged involvement in the case.

The Central Bureau of Investigation took over the probe into the trainee doctor's rape-murder from the Kolkata Police last week upon directions of the Calcutta High Court.