The CBI on Monday started a second round of polygraph tests on former RG Kar Medical College and Hospital (RGKMCH) principal Sandip Ghosh and five others as part of their investigation into the rape-murder of a woman doctor at the institution.

According to an officer, over the last 10 days, Ghosh provided inconsistent answers during questioning, prompting officers to conduct another round of polygraph tests.

The CBI initially conducted the lie-detection tests on Ghosh and five others on Saturday, followed by a test on arrested accused Sanjay Roy at the Presidency Correctional Home on Sunday.

Additionally, Ghosh and former medical superintendent and vice-principal Sanjay Vashisth are also being investigated for alleged financial irregularities within the institute.

The case centres on the rape-murder of a postgraduate trainee woman doctor in the seminar hall of the hospital on August 9. A civic volunteer was arrested in connection with the crime the next day. The gruesome crime resulted in nationwide protests by doctors and citizens.

On Sunday, the CBI searched Ghosh's and Vashisth's homes, with Ghosh presenting files and documents at the central agency's office in Salt Lake on Monday morning. Vashisth appeared at Nizam Palace, where a forensic medicine department professor was also questioned.

The agency also searched 13 other locations in Kolkata, including residences and offices of people involved in patient care and management supplies connected to the hospital.

"After yesterday's search operations, we have several questions for them," the officer told PTI.

This action follows a complaint by Akhtar Ali, former deputy superintendent of RGKMCH, alleging that Ghosh and his associates issued issued tenders for the construction of food stalls, cafes, canteens, and urinals without the permission of the health department and the college council.

Initial probe revealed that three traders got these "illegal" tenders, the officer said.

The CBI started the investigations into both the murder and the alleged financial irregularities on the direction of the Calcutta High Court.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.