A Bollywood thriller that focuses unsqueamishly on the caste divide in modern-day India has fought off attempts from critics to get it banned - and proven a success at the box office in the process.

Article 15, from director Anubhav Sinha, follows the story of a real-life event in 2014 when two minor girls from the Dalit (formerly Untouchable) community in Uttar Pradesh state were gang-raped and murdered by men from a “higher” caste.

The apparent motive for the crime, in both the movie and in real life, was to send a message to other Dalits about remembering their place. The girls, farm-labourers, had asked for a 3-rupee (3p) raise to their daily wages.

The film begins with the murders and then follows the attempts of urbane, educated - and upper caste Brahmin - police officer Ayan Ranjan (Ayushmann Khurrana) to solve the case and find a third missing girl, in the process unpicking the caste-riven village society that led to the crimes being committed in the first place.

Since its 28 June cinema release, the movie has grossed an impressive 500m rupees (£5.8m) and won praise from film critics, with India Today’s Lakshana Palat calling it “an uncomfortable watch [that] makes you squirm when it shows you the caste discrimination in the country”.

Remarkably, the film appears to be the first mainstream, Hindi-language movie to tackle the issue of caste-based violence and atrocities head-on. That’s despite the fact that, according to the National Crime Records Bureau of India, four Dalit women are raped every day across the country.

Recent attempts by film-makers to at least reference caste issues include the lauded Marathi-language movie Sairat (2016). But a Hindi remake in 2018, Dhadak, was panned as a watered-down version that skirted round the core issue of love across caste barriers.

Not everyone is happy to see the caste divide exposed under the Bollywood lights. Some Hindu nationalist groups, which have strong roots in Uttar Pradesh, have said they would have tried to block its filming on location in the state had they known the full details of the plot, in which the villains turn out to be Brahmins.

The day after release, the Brahman Samaj of India (BSOI), a national association for the upper caste community, filed a petition in the Supreme Court demanding the film’s licence be withdrawn.

In its 11-page petition, the BSOI said the “objectionable dialogue” of the film would itself incite hatred against Brahmins and violence between castes.

Their main complaint is that while Brahmins are among the antagonists in the movie, the accused in the real-life 2014 rape case were from a “general” caste - in other words, neither upper or lower.

The petition also took issue with the film’s name, with Article 15 of the Indian Constitution prohibiting discrimination on grounds of religion, race, caste, sex or place of birth. The petitioners claimed that association with the “anti-Brahmin” movie would cause “severe damage to the public perception of Article 15 and its origin (the Constitution)”.

This week, the Supreme Court dismissed the petition, saying the association should take the matter up with the body that licensed the film in the first place, the Central Board of Film Certification.

But Dr Judith Anne, programme research coordinator for the National Dalit Movement for Justice (NDMJ), told The Independent there were reports of right-wing activists taking the law into their own hands, forcing cinemas to stop showing the film in her home state of Uttar Pradesh.

“This movie represents progress. It is really saddening that people are trying to get it banned, and it is part of a trend - that as soon as you start talking about rights, or abuses, or atrocities, others say you are putting the country down.

“If they don’t want to see movies like this then it really reinforces the point that the film is trying to make - that people are not willing to accept that caste issues are there.”

Dr Anne said it was a positive thing that the film was opening up conversations around caste and that the film had some strong Dalit characters - though such is the underrepresentation of Dalits in Bollywood that none are played by Dalit actors.

And she repeated a point that many critics have made - why did the film’s downtrodden Dalit community need a Brahmin hero to save the day?

“At a point the film takes a dramatic turn where the police officer (played by Khurrana) is the only one left with the entire role of caste emancipator,” she said. “In the end it shows it is the Brahmin who is the liberator - it is not really showing that the [Dalit] community can fight for itself.”

The director, Sinha, has in previous interviews defended making his protagonist upper-caste, insisting the message is not that “only Brahmins can save Dalits”.

There is a scene in the movie where Khurrana is standing in the middle of the rural police station, having to have his own caste status and therefore his place in the social hierarchy explained to him - as an outsider from the urban elite, he had no idea. His response, one that might mirror that of many people when first informed of India’s existing caste divisions, is to cry out: “What the f*** is going on here?”

Sinha told the Indian Express that his target audience for the film were not the caste-riven rural communities themselves, but rather educated young people who were not aware such things still went on.