In the mysterious death of journalist Nirupma Pathak, the findings of Gupta changed the course of the investigation.
Like Sushant Singh Rajput's case, the media had raised questions over Nirmala's death. Was it a murder or suicide?
Media reports based on a few witnesses alleged that Nirmala, a Koderma (Jharkhand) based scribe, was the victim of honour killing and had been murdered by her parents.
Under public pressure, Nirmala's mother was arrested on charges of murder and sent to jail. However, forensic re-examination of the case by the AIIMS team concluded that Nirmala, who worked with a Delhi based business daily, had committed suicide. Nirmala's mother was finally acquitted.
Refusing to talk in detail over the Sushant case, Gupta told IANS, "It's a very sensitive case. Public sentiments are with the deceased's family. I will not speak on any issue related to the investigations."
However, sources in the forensic department revealed that the CBI and forensic experts will first examine the lapses in the initial probe. Tampering of any evidence on the scene of crime or omission of any sign of foul play will be key areas to ascertain whether Mumbai Police or the panel of doctors conducting the post-mortem or any other suspect tried to suppress any tell-tale sign in Sushant's mysterious death.
A team of doctors, including two forensic surgeons, Shiv Kumar Kolle and Sachin Sonawane, which conducted an autopsy of the body on June 15 at the Cooper Hospital in Mumbai, had concluded that Sushant died of asphyxia due to hanging.
In their autopsy report, the panel of five doctors did not indicate any sign of foul play or observed any trait or feature which led to suspicion of murder.
However, once the videography and photos (if taken) of the autopsy are re-examined by the forensic team from AIIMS, the picture would be more clear, a source in AIIMs said.
Most probably the panel of forensic experts from AIIMS and the panel of doctors at Cooper Hospital, which conducted the post-mortem, will have a thorough discussion over the seven-page autopsy report before arriving at any conclusion on the cause of the Bollywood star's death.
Sources in the CBI said that once all documents, case dairies, and witnesses' statements are studied, the agency would first look into if any outside hand was involved in the case.
"The CBI is known for handling sensitive cases. We do not succumb to pressure. We are investigating the case with an open mind. Whether Sushant Singh was murdered or he committed suicide, only documentary and forensic evidence will prove," said an officer in the agency.