Five years ago, Sunny Leone was a moderately successful Canadian porn star. Today she is one of Bollywood's most in-demand actresses, earning millions of rupees as she fills cinemas, hosts her own television shows and endorses lucrative brands.

Her new film, Mastizaade, opened in around 2000 cinemas, after its trailer had been viewed a record 13 million times on YouTube. Despite terrible reviews, a sequel is already planned.

India - where matrimonial ads placed by parents in newspapers are listed by caste, homosexuality remains illegal, and even public displays of affection are strictly taboo - appears to have fallen in love with a porn star.

"We never had someone like Sunny Leone before, that's for sure," said Prabhat Choudhary, who runs leading Bollywood talent agency Spice PR.


"She is not just getting work, but societal acceptability. She has become a mainstream celebrity."

So how did this happen in India, a country renowned for its fiercely traditional attitudes to sex and marriage?

Ancient India may have given the world the Kamasutra, but puritanism has been the order of the day at least since the British arrived, and possibly as far back as the invasion of the Muslim Mughals.

Until recently, that has showed little sign of abating. For many, the rise of Leone is a sign of change.

"Taboos around sex are lifting," said author Ira Trivedi. "The sexual revolution in India is happening all at once."

The signs are there to see, particularly among India's middle class.

Arranged marriages, though still commonplace, are on the wane, while divorce rates are soaring.

Dating apps have penetrated far beyond metropolitan Mumbai, and pre-marital sex in cities has skyrocketed. Even the film censors are beginning to relax.

Whether prompted by the internet, demographic change, or economic liberalisation, India's moral compass on carnal matters is in flux.

According to the PornHub website, Indians are the third-highest consumers of porn, after the United States and Britain.

"We're a sexually curious society," said Trivedi.

Which is where Leone comes in. She is not only the most searched-for porn star in India, she is the most searched-for person full stop, and has been for four years in a row.

Last week, Leone's stock rose further after an interview with an Indian news channel in which she was subjected to repeated, aggressive questioning about her background.

CNN-IBN's Bhupendra Chaubey asked Leone if she felt responsible for "corrupting Indian minds and morality".

While the interviewer was condemned as misogynistic and prurient, Leone won plaudits for standing her ground, refusing to express any shame or regret. "I can leave if you want me to," she reassured Chaubey.

The interview has been watched more than a million times, and the messages of support on social media are almost as numerous.

Aamir Khan, Bollywood's most bankable actor, was among many to side with Leone.

Her unlikely story began in the small Ontario city of Sarnia.

Born Karenjit Kaur Vohna to Punjabi Sikh parents, Leone was studying to become a paediatric nurse when she was introduced to a Penthouse photographer.

Soon she signed a contract with porn company Vivid Entertainment and began making adult videos.

It was her 2011 appearance on Big Boss, the Indian equivalent of Big Brother, that launched her unlikely new career in her adopted homeland.

She avoided telling her housemates her true profession, describing herself as an "actress and model". But soon her first Bollywood contract was on the table, and India had its new poster girl.

Of course, much of Leone's popularity still derives from the availability of her previous work online.

And so Leone seems set to dominate screens in India for the foreseeable future.

"I don't think Indians will be encouraging their daughters to become porn stars," said Choudhary. "Yet at the same time we have accepted Sunny Leone as an individual, and that is heartening."

-Telegraph Group Ltd