A local court here on Sunday sent former principal of RG Kar hospital Sandip Ghosh and Tala police station officer-in-charge Abhijit Mondal to CBI custody till September 17, an officer said.

Both Ghosh and Mondal were produced before a court by the central agency in connection with the rape-murder of a doctor at the state-run hospital.

"We have got their custody for three days till September 17. Now, both will be questioned together. The duo played vital roles in the RG Kar case," the officer told PTI.

The CBI, probing the case, had on Saturday evening arrested Mondal and added charges of evidence tampering against Ghosh, who is currently in judicial custody in a corruption case related to RG Kar hospital.

Mondal also faces accusations of tampering with evidence, delaying registration of the FIR, and other related offences, according to the officer. The RG Kar Medical College and Hospital falls under the jurisdiction of Tala PS.

The police officer was held after he "failed to provide satisfying answers" during questioning by the CBI officers on Saturday.

In the court, the CBI claimed that "there could be a bigger conspiracy" and that both Ghosh and Mondal had played some "vital roles" in this crime.

Both were charged under relevant sections of the Bharatiya Nyaya Sanhita for disobeying lawful orders as public servants, tampering with evidence, and criminal conspiracy.

The two were in touch with each other, with Ghosh giving instructions to the police officer on how to proceed with the rape-murder case, the CBI said.

Mondal was informed about the death of the doctor around 10 am on August 9, but the FIR was lodged after 11 pm. The duo tried to "downplay the incident" as well as "shield" the heinous crime, it said in court.

The agency also said police should have treated it as a suo motu case at the outset, since it's a rape-murder case.

The CBI arrested Ghosh on September 2 in connection with financial irregularities at the hospital.

The body of the postgraduate trainee was found in the seminar hall of the state-run hospital on August 9. To date, three persons have been arrested in this connection.