CBI officials have asked former principal of state-run RG Kar Medical and College and Hospital, Sandip Ghosh, to appear before them for questioning for the third consecutive day in connection with their probe into the rape and murder of a woman doctor.

Ghosh, who was grilled for nearly 13 hours on Saturday, from 10 am till past midnight on Sunday, has been asked to come again this morning as CBI sleuths have several more questions for him, an officer of the investigating agency said.

"The former principal has been asked to come again today at 11 am. We have a list of questions for him," the Central Bureau of Investigation (CBI) officer told PTI.

Ghosh was asked to specify his role after getting the news of the death of the doctor, who he had contacted and why he made the parents wait for nearly three hours, he said.

The ex-principal was also questioned who had ordered the renovation of the rooms near the seminar hall at the emergency building of the hospital after the incident.

"We are trying to find out whether there was any conspiracy or pre-planning to the crime. What was the principal doing and whether he is involved with the incident in any manner," the officer said.

The CBI sleuths would be verifying Ghosh's replies with the versions of other doctors and interns who were on duty along with the deceased doctor at the chest medicine department on the night of the incident.

So far, CBI has grilled over 20 people, including a couple of officers of the Kolkata Police, in connection with its investigation.

Ghosh declined to take any question from the media while leaving the CBI office at CGO Complex in Salt Lake past midnight on Sunday.

The CBI officers grilled Ghosh first on Friday and then for around 13 hours on Saturday in connection with their investigation.

The former principal had resigned from the post two days after the woman's body was found on August 9. He had expressed fears of being attacked, prompting his lawyer to seek protection from the Calcutta High Court. The court directed him to approach a single bench.

The body of the post-graduate trainee doctor was found in a seminar room at RG Kar Medical College and Hospital on August 9. Police arrested a civic volunteer the next day in this connection.

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