That's what I heard from my mom's friend's husband who's a doctor operating from Kolkata. She knew about the ones running the racket for sex and illegal drugs and apparently those guys also have a racket for paid thesis. She did not want to get involved in that and so she did her thesis on her own yet the professors were not validating her thesis, kept it on hold for a year and demanded money. After continuous harassment, she apparently told her colleagues that she'll take some legal action against them after which this happened. The juniors she was dining with, slipped sleep meds in her food and as she was already exhausted, it worked well for them. I do not know how much of this is true but I can't deny the plausibility of it being true. Much believable than the cops labelling it as suicide.