Parents of the 31-year-old postgraduate trainee who was raped and killed at RG Kar Medical College and Hospital in 2024 submitted a fresh petition before the Sealdah court on Tuesday, saying they were still of the opinion that Sanjay Roy could not be the only person behind their daughter’s death.

They demanded a detailed inquiry into the role of others who were with their daughter on the night of the incident.

The parents have also sought the arrest of assistant sub-inspector Anup Dutta, whose name emerged after Roy’s arrest in 2024.

Dutta, who is attached to the welfare wing of Kolkata Police, was the first Roy had met after the commission of the crime and had given him a place in his Salt Lake barrack.

Roy was later arrested from the same barracks.

“We are of firm belief that Sanjay Roy could not have done this alone to my daughter. We want the role of the other persons who were there that night to be probed. We also want the arrest of ASI Anup Dutta,” said the father of the deceased doctor.

Dutta had been questioned several times by the CBI, but the central agency did not find it necessary to name him a suspect. The parents on Tuesday expressed their disappointment over the role of the CBI in handling the case and accused it of playing a “biased role” in the “larger conspiracy”.

They also raised questions about the Roy’s polygraph test reports, which CBI had used to nail Roy as the lone accused in the case.

The matter will be taken up during the next hearing date.

In August 2024, an on-duty postgraduate trainee was found brutalised and murdered inside the seminar hall of the emergency building of RG Kar Medical College and Hospital.

The city police had taken up the probe of the case and arrested Roy, a civic volunteer of Kolkata Police, the next day. A few days later, the CBI took over the probe but maintained that Roy was alone in the commission of the crime.

Till now, Roy is the only person to have been convicted and sentenced for life in this case.