Gupta said he would soon interact with the media, as per lawful procedure, to clarify his stand.
"I'll answer according to the government's rules and the rights of a government servant... My duty is to pursue the truth in the Sunanda Pushkar's post-mortem case," Gupta said.
Gupta had reportedly written to AIIMS Director M C Mishra, seeking his permission to interact with the media to clarify his stand on the issue.
"I stand by what I said. Even after the autopsy and before the cremation I had said that this was a case of unnatural death. If someone has a problem or slightest doubt over the autopsy report prepared by me, they can go for a second autopsy," Gupta said.
Gupta, who led the panel that conducted Sunanda's post- mortem, had alleged that he was pressurised to show her death was natural, which he resisted.
Sunanda, wife of former Union Minister Shashi Tharoor, was found dead in a five-star hotel in South Delhi on the night of January 17, a day after her Twitter spat with Pakistani journalist Mehr Tarar over an alleged affair with Tharoor.