Not so long ago a woman from Bradford arrived in London’s Baker Street tightly gripping a small box. Inside was an engagement ring intended for her true love. Nothing peculiar about this story so far. Until you learn the object of her affection was not a person but a Madame Tussauds waxwork model of the dimple-cheeked Bollywood legend Shahrukh Khan, whose acting career spans more than 25 years and includes 60 films, most recently the melodramatic blockbuster Om Shanti Om.

“It was a little weird,” admits Nicky Marsh, marketing director for Madame Tussauds. Marsh says she was taken aback by the proposal, even though she is no stranger to weird experiences involving waxwork models of the famous. She has, for example, witnessed frenzied teenage girls jump up and down in front of R’n’B star Usher’s waxwork and a woman sob with sorrow in front of an imitation of the late Palestinian leader Yassir Arafat. Neither was the strength of devotion to Khan a complete surprise. So many fans have already made the pilgrimage to see his waxwork that a special stage has had to be erected.

Bollywood has joined Hollywood as a source of keen fascination for the millions of visitors that pass through the doors of Tussauds each year. Before Shahrukh Khan was installed last year, Indians were the sixth largest overseas visitor group to the attraction. Since then, they have become the third largest, behind visitors from the US and Germany. And on Tuesday, as part of its continuing campaign to lure the domestic and overseas Asian market, Madame Tussauds unveiled a model of the tousle-haired film star Salman Khan.

Early signs are that this model is likely to be as successful as its predecessors. Hundreds queued in torrential rain, hoping to catch a glimpse of Salman Khan, 42, star of more than 55 films, who was there to unveil his waxwork double. On his departure, his car was chased by women running down Baker Street.

Professor Rachel Dwyer, an expert on Indian culture and cinema, from London University’s School of Oriental and African Studies, confirms that Bollywood stars are “treated like gods” in India. “The Indian media is devoted to them.” She says the hierarchy is: “Film stars, then cricket stars, then MPs and, perhaps then, celebrity industrialists.”

Gossip magazines, she says, are a good barometer of the differences in celebrity culture between Britain and India. “India, unlike Britain, does not have a Heat magazine culture,” she says. “Reality TV stars exist but the national obsession, unlike Britain, is not there.”

The shelf life of Bollywood celebrities – Salman Khan made his film debut 30 years ago – is another part of their appeal to Madame Tussauds. As British tabloids and gossip magazines demand an ever-faster supply of celebrities, home-grown stars’ fame can be fleeting. Creating a wax copy of someone whose fame wanes shortly after is an expensive mistake – each waxwork takes four months to make and costs about £150,000.

Even so, the London attraction is likely to remain devoted to celebrity for a while. Ben Lovett, Madame Tussauds’ spokesman, explains the mix of exhibits reflects the culture and interests of the waxworks’ locations. Washington has politicians, Berlin has sports stars and London has the royals and the Beckhams because “Britain is immersed in celebrity culture”.

Indeed, such is London’s focus on the famous that in 2006 the Planetarium, which had taught generations of schoolchildren about astronomy and space exploration since the 1950s, devoted itself to stars of a different firmament by offering visitors the chance to attend a photo shoot with “Kate Moss”, then mingle with “Brad Pitt”, “Angelina Jolie” and other stars at a premiere party.

In this climate, even prime minister Gordon Brown is not an automatic choice of model: the first PM who has not been instantly installed in the hall of fame. Why not? “It takes time to make a model. There’s a limit to how many will be produced each year,” says Lovett. “We ask guests who they want to see. We also look at media impressions and try to consider who is of public interest. Generally, we think prime ministers should win the election before they go in – it’s a verdict of people power.”

The selection process for Salman Khan’s model marked a new triumph of “people power”. It was the first time such a decision had been determined by the public. Visitors were asked to vote in a poll conducted last August by Madame Tussauds alongside British Asian entertainment magazine Ikonz and BBC Asian Network. Khan’s 10,000 votes far outstripped the runner-up Madhuri Dixit. The poll generated such interest from the public, the tourist attraction is considering doing it again.

Normally, selection and deselection meetings at Tussauds are fiercely private. My requests to sit in on selection meetings were refused. A former employee, who worked there for more than a decade, says even other employees were often kept in the dark until the last moment about who the next waxwork would be.

Surveys and polls are not the only way of finding out what the public wants. Some feedback from visitors is based on wear and tear. If tourists stopped squeezing Brad Pitt’s bottom, for instance, the maintenance department would testify to his diminishing popularity. The wardrobe department underestimated Justin Timberlake’s attractiveness to their cost. He used to wear a tailored Savile Row white suit but it became so quickly stained by lipstick kisses it had to be replaced with a sensible brown cardie.

Which brings us to the puzzling question of why people want to kiss Timberlake’s model or get engaged to an imitation of an Indian film star?

Kavisha from Sri Lanka says she has come to see Brad Pitt and that she’d never get a chance to meet the actor in person. Would you like to meet the real Brad Pitt? “No!” she shrieks. “I wouldn’t know what to say to him.”