Abhijit Mondal, the arrested officer-in-charge of Tala police station and Sandip Ghosh, the former vice principal of RG Kar Medical College and Hospital were not directly involved in the commission of the crime of rape and murder of the junior doctor but they may have been a part of a larger conspiracy, the CBI said on Tuesday.

Presenting the case before the Sealdah court, where both Mondal and Ghosh were produced, the CBI lawyers said the former principal did not visit the crime scene even after knowing about the incident and there were procedural lapses on the part of the officer-in-charge.

The lawyer representing the central investigating agency told the court that there wasn't enough evidence to suggest it was a case of gang rape at RG Kar Medical College and Hospital. But the investigations are still on and there is a need to collect more information by taking Mondal and Ghosh in custody and questioning them, the CBI said.

Metro reported earlier that the CBI was yet to gather enough evidence to suggest the 31-year-old junior doctor's rape and murder was an act involving more than one person.

"Despite reaching the medical college and hospital on the morning of August 9, Sandip Ghosh did not care to visit the seminar room where the junior doctor was found dead," the CBI lawyer told the court. "This appears to be a deliberate act."

Investigations so far have revealed that Ghosh called Mondal at 10.03am on August 9 and the medical superintendent cum vice principal (MSVP) of the hospital lodged a written complaint with the Tala police station at 2.55pm.

The CBI's lawyer told the court that the first General Diary mentioned that the postgraduate trainee at RG Kar was found lying unconscious in the seminar room of the chest medicine department.

"Was this deliberate and a part of a larger conspiracy? We need the two in custody to interrogate and find out the truth," the lawyer said.

The court wanted to know from the CBI if the two accused were not directly involved in the commission of the crime, why CBI was not drawing up a separate FIR.

The lawyer said the preliminary findings were a part of the ongoing probe into the case of rape and murder and the role of the police officer and the former principal remained crucial here.

Mondal's lawyer said that the CBI has seized some of his mobile phones and collected some CCTV footage.

"But does this require custodial questioning," he asked the court.

"The officer has appeared for questioning every time he was summoned," he told the court.

After hearing both sides, the judge remanded the two to CBI custody till September 20.