Sources said 74-year-old Pachauri was questioned at his posh Golf Link residence in New Delhi by a three-member police team which carried a questionnaire consisting of nearly 50 questions covering different aspects of the charges levelled against him by the researcher.
"He was asked specific questions about his claims that his various social media accounts were hacked by someone to send objectionable messages to the victim," a source said while declining to elaborate on Pachauri's responses to the questions.
Investigators had already sent Pachauri's mobile and laptop, submitted to police by him, for forensic analysis as he claimed that he was a victim of hacking and his computer resources were misused and filed a police complaint in this regard as well.
A senior officer associated with the investigations said that the questioning of Pachauri is not yet complete and they may again grill him soon.
"The next questioning may take place on Friday," he said.
On May 21, a local court had declined to allow Pachauri to enter his office while noting the slow progress in the probe against him and asked police to complete it by July 17.
The court had noted that investigation in the case was progressing at a "snail's pace" as during the arguments, the Investigating Officer (IO) had conceded that from March 21, no probe had been done.
The court had also said that the IO may conclude the probe by the next date of hearing and examine material witnesses of the prosecution.
Pachauri was granted anticipatory bail on March 21 by the court which had rejected the request of police for his custody in the molestation case.
The court had granted him anticipatory bail by imposing several conditions on him including that he will join the probe as and when called, he will not enter TERI office premises and not intimidate or threaten the complainant and the witnesses of the case.
On February 13, an FIR was registered against Pachauri on charges of sexual harassment under sections 354, 354(a), 354(d) (molestation) and 506 (criminal intimidation) of the IPC at Lodhi Colony Police Station after the woman had submitted a 33-page complaint in this regard to the police.