The parents of the 31-year-old postgraduate trainee who was raped and murdered at RG Kar Medical College and Hospital last year are travelling to Delhi to meet CBI director Praveen Sood.

The parents said they were expecting to meet the agency’s topmost officer and express their concerns about the delay in the submission of a supplementary chargesheet in connection with the case.

“We have emailed the CBI director seeking an appointment with him but we are yet to receive a response. We are still going to Delhi on Thursday with the hope that we will be able to meet the director or someone deputed by him,” the slain doctor’s father said on Wednesday.

Tamonas Chaudhuri, a doctor who will accompany the parents, said the email was sent on Monday.

“We hope they will meet us and hear the parents. We will tell them that the supplementary chargesheet is still pending. We will also make some points about the probe, things that the Sealdah court had also mentioned in its verdict,” Chaudhuri said.

The CBI had recently submitted a status report before the court in Sealdah that is hearing the case, saying they would submit the supplementary chargesheet soon.

The central agency had previously arrested the former principal of RG Kar Medical College and Hospital, Sandip Ghosh, under whose watch the crime was committed, and the then officer-in-charge of Tala police station, Abhijit Mandal, for alleged destruction of evidence.

However, both received bail after the agency failed to file charges within 90 days.

The victim’s father said the central agency had already made a “considerable delay” in the submission of the supplementary chargesheet.

“The more the delay, the more evidence is getting tampered with. We want to talk to the top CBI officers about that. We are not leaving any stone unturned,” said the father.

The CBI had submitted a chargesheet which mentions the involvement of one person — Sanjay Roy — in the rape and murder case. However, the chargesheet also mentioned that a supplementary chargesheet would be submitted against Ghosh and Mandal if proof of destruction of evidence was found against them.

While Roy has been convicted for life based on the initial chargesheet, the victim’s father worries that continued delays may lead to evidence tampering. The promised supplementary chargesheet is expected to address allegations of “larger conspiracy” against Ghosh and Mandal.