The Bollywood star, a suicide … and an online witch-hunt across India

It was a muted finale to a saga that has rivalled the wildest movie storylines. On Wednesday, the Bollywood star Rhea Chakraborty stepped out of the Byculla women’s prison in Mumbai, released on bail after 28 days in jail.

Over the previous four months, she had been vilified in a media spectacle that became a national obsession in India. She was accused of playing a role in the death of her boyfriend, fellow Bollywood star Sushant Singh Rajput, 34, who killed himself in his apartment in Mumbai on 14 June.

After news of his death broke, Rajput’s struggles with mental health began to emerge. But in the days that followed, conspiracy theories also began to take hold that Rajput had been driven to his death by the nepotism in India’s film industry, which had hated him for being an outsider and not from pure Bollywood lineage.

Related: Sushant Singh Rajput: actor's death fuels media frenzy in India

Claims that he had been murdered spread on social media and a “Justice for Sushant” campaign took hold, seized on by politicians from the ruling Bharatiya Janata party (BJP).

The glare of the media then turned to Chakraborty. Rajput’s family filed a lawsuit against her, claiming she had abetted his death, and though no evidence could be presented, a campaign of hate began to build against her. In September she was arrested by the Narcotics Control Bureau (NCB), accused of supplying drugs to Rajput, trafficking, and being part of an “active drug syndicate”.

She was not alone. After her arrest, the NCB also questioned some of Bollywood’s biggest names for alleged drug-related activity.

But Chakraborty denies any wrongdoing, both in relation to the death of her boyfriend and the NCB’s charges, and last week the All India Institute of Medical Sciences (Aiims) released an autopsy report confirming what the police had said all along: that Rajput had died by suicide. Any suspicion of murder could be ruled out.

Shortly after, a court in Mumbai ruled that Chakraborty, who had no criminal record, was not part of any syndicate and could not be said to have financed or supported illegal drug trafficking, as alleged by the narcotics agency. She was therefore released on bail after almost a month behind bars.

As the conspiracy theories unravel in the face of science and the legal burden of proof, a pushback has begun. Last week, Mumbai police, who have born the brunt of online accusations of a cover-up, filed two reports under India’s Information Technology Act alleging that over 80,000 fake social media accounts had been used to derail their investigation. A report released by Microsoft Research India also laid out the role BJP politicians appeared to have played in fuelling conspiracy theories around Sushant’s death for political gain.

According to the data, BJP politicians helped manipulate the narrative around Rajput’s death online as an attempt to discredit the opposition Shiv Sena party, which governs the wealthy state of Maharashtra, where Mumbai is located. The BJP and Shiv Sena are former political allies turned bitter rivals in the state.

Among the conspiracies being peddled was that Shiv Sena was involved in the death, and the chief minister was collaborating with police to cover up Rajput’s murder and their own bungled investigation.

Among the findings of the Microsoft report, which analysed data from Twitter, YouTube and an archive of widely shared fake news, was how politicians, specifically the BJP, “were instrumental in changing the course of the discourse by referring to the case as ‘murder’, rather than ‘suicide’”.

“Over the weeks that followed, there was an increased usage of ‘murder’ keyword repeatedly in tweets by BJP politicians … Overall, the data strongly suggest that the BJP drove the insinuation of ‘murder’,” the report states. It adds that it appeared “far from coincidental that a lot of the celebrities being trolled in the aftermath of the suicide were among those who were critical of the government in the past.”

The report also notes that among the online groups claiming to seek justice for Rajput, researchers found “a heady mix of ultranationalism, casteism, distrust of Muslims, and misogyny.”

The report has been subject to such a vicious online backlash that its authors told the Observer they no longer had permission to speak to the media.

And even all this has not laid the speculation to rest. The Mumbai police investigation into Rajput’s death continues, as are the investigations by the Central Bureau of Investigation, the Enforcement Directorate and the NCB. Chakraborty’s brother remains in jail, and a court date has yet to be set for Chakraborty, who still faces charges of procuring drugs. Meanwhile, the Rajput family’s lawyer has claimed the Aiims report “lacks credibility” and that they intend to challenge it in court.

In the UK and Ireland, Samaritans can be contacted on 116 123 or email jo@samaritans.org or jo@samaritans.ie. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at www.befrienders.org