Kolkata | Central Bureau of Investigation (CBI) officers on Monday interrogated Trinamool Congress MLA Nirmal Ghosh for nearly seven hours in connection with their ongoing investigation into the alleged rape-murder of a medic at RG Kar hospital here last month, officials said.

They also questioned the hospital's forensic department doctor, Professor Apurba Biswas, in connection with the case, they said.

The postgraduate trainee was allegedly raped-murdered inside the state-run RG Kar Medical College and Hospital here on August 9.

Ghosh, TMC's Panihati MLA, reached the CBI's CGO Complex office in Salt Lake around 10.30 am.

"I had certain things to tell the investigating officers and they also needed to know certain things from me. I was there at the RG Kar Hospital as an MLA. She was a doctor from my assembly constituency. I want the criminals to be hanged. I also want justice for her. She was a brilliant girl," Ghosh told reporters.

Ghosh is suspected to have played "an important role in arranging the hasty final rites of the deceased doctor", the CBI officer said.

"We had summoned him for questioning on the incident. He was seen at the hospital and also at various other places including the crematorium (on that day)," he said.

"We have got the call details and found that there were talks between the arrested ex-principal of the RG Kar Hospital Sandip Ghosh and Nirmal Ghosh on August 9. We need to know the details of their conversations," he said.

Three persons, including the former principal of the hospital, have so far been arrested in the case.

Meanwhile, a local court on Monday extended the jail remand of Sandip Ghosh and three others until October 7 in connection with the financial irregularities case at the hospital.