Rajput was found dead aged 34 at his home in Mumbai earlier this year in June, with reports indicating that his death was by suicide.
His family, however, lodged a formal police complaint accusing Chakraborty of abetting the suicide.
According to the BBC, Chakraborty has now been arrested by India’s narcotics control authority for allegedly buying drugs for Rajput.
The 28-year-old has not issued a statement but has previously denied any wrongdoing or involvement.
Her brother, Showik, and Rajput’s house manager, Samuel Miranda, were also arrested last week, however, the charges against them have not yet been revealed.
All three are reportedly accused of organising and financing Rajput’s alleged consumption of cannabis.
The Narcotics Control Bureau described Chakraborty as an “active drug syndicate”. Her bail plea was rejected and she will remain in custody until 22 September.
Chakraborty’s arrest follows a highly-publicised case that has polarised India in recent months. Since Rajput’s death, many people, including some of India’s most high-profile journalists, have suggested that Chakraborty was the cause, claiming that she “drove Sushant to suicide”.
Conservative television hosts have called Chakraborty “manipulative” and accused her of performing “black magic”. The actor has been receiving similar abuse on social media.
The Bollywood actor has appealed to India’s Minister of Home Affairs Amit Shah for a fair investigation into Rajput’s death. She has also approached the Supreme Court over the “unfair media trial” against her.
At the time of her arrest, Chakraborty was seen wearing a t-shirt which read: “Roses are red, violets are blue, let’s smash the patriarchy, me and you.” The words have been shared by fans and fellow Bollywood stars in a show of support for the actor.
Conversely, others have celebrated the arrest on social media. Rajput’s sister, Shweta Singh Kirti, who has been vocal on Twitter calling for Chakraborty’s arrest under the hashtag “#ArrestRheaNow”, responded to the news with a post, stating: “#GodIsWithUs”.