The first thing that catches Roshan's eye as he survey's the cityscape is a poster for the Stephen Chow Sing-chi blockbuster Kung Fu Hustle. And behind the poster lies the reason for his trip to our shores. He says he recently got a chance to see the film - but he didn't just watch it, he studied it. 'The action scenes were mind-blowing,' he says.

Roshan is in town to work under the expert eye of Tony Ching Siu-tung, the action choreographer on the Oscar-nominated House of Flying Daggers and the box-office smash Hero. Ching is preparing Roshan for the sequel to last year's Bollywood hit Koi Mil Gaya (I Found Someone). For four to six hours a day, Ching has been unveiling the mysteries of wushu to Roshan at the Pacific Club gymnasium.

'I didn't make an announcement about coming because I'm here to learn and it's been nice getting around, making a few friends,' says Roshan. 'Everyone here is busy doing their own thing and so am I.'

Seated on a mat during a break in training with his translator/assistant at his side, Ching says: 'When the producer/director Rakesh Roshan [Hrithik's father] first came to meet me last year with the proposal of working on an Indian film, I agreed immediately.

'I've seen a few Indian films and really enjoyed them. They like good action, as do we. So it's a good mix. Even before we negotiated terms, I wanted to do it, just for the opportunity. I went to India on a location-hunting trip with the crew and I had a great time.'

Roshan Jnr is hesitant to state when shooting begins, but, as it's his father's film, he will be actively involved in all aspects of the production.

'I've been behind the scenes for many years, even though I always wanted to be an actor, I've been assisting my dad for a long time so I know what it takes,' he says. 'This is my third trip to Hong Kong over the past 14 months and we were here working with the local film fraternity, and the Hong Kong Tourism Board, to promote Bollywood film production in Hong Kong.'

Unfortunately, though, this is one production which will not be shot here as the filmmakers have decided to split their time between India and Singapore. 'The reasons were simple - we were given more incentives to shoot there,' says Roshan. 'It wasn't as economically viable to shoot here, and the location there suited the script so it's been settled in Singapore. But we still wanted to work with talent like Tony, to give the film a Hong Kong flavour, so all the film's action scenes will be choreographed by him and his crew.'

While Roshan's foray into film could have been predicted - Rakesh Roshan was an actor in the 1980s, and is one of the most successful producer/directors working today - the amount of success he's enjoyed has surprised even the most seasoned of Bollywood watchers.

His first film in a leading role was 2000's Kaho Na Pyar Hai (Say There's Love), which was that year's box-office champion and won its star both the best newcomer and best actor awards at the Filmfare Awards - India's equivalent of the Oscars. Koi Mil Gaya followed in 2003 and history repeated itself: the film was box-office gold and Roshan walked away with the critic's choice award for best actor. 'Now I can afford to wait for good films to come around,' he says. 'My next meal doesn't depend on how many films I have at hand. Choosing the right film for me is a luxury.'

Roshan's regime is rigorous. He has started from scratch and is spending four to six hours a day under the command of Ching and two of his trainers. 'I didn't know what to expect when he first came to lessons, I've never worked with an Indian actor,' Ching says. 'But he's been dedicated, focused and hard-working.'

Three hours into the session and Roshan is still going full throttle. During one air-swivel exercise, Roshan's sword clips a trainer's ear and he smiles apologetically, mildly embarrassed at the goof.

'I've had so many injuries,' he says. 'Every muscle in my body has been pulled, stretched, hurt. I've damaged muscles I didn't know I had. My wrist,' he says pointing to bandages, 'I don't think I've broken it ... but it hurts.'

Rehearsals are taped and Roshan rushes to review his progress during his break. Ching has it all on tape for different reasons. 'I'll go back and watch it all again to see what suits him,' he says. 'We've had limited time, as we do with any film, so I have to work with what we have. He's been an excellent student and on camera we will focus on what he does well and those are the things I will choreograph into the film when we begin shooting.'

Ching and his team are now busy preparing for a trip to Mumbai for further work on the film. 'With CGI, wire-techniques and other effects, it's like working on an international film - we've had no restrictions on what we can do,' he says.

The Oscar-nominated Lagaan (2001), the blockbuster Devdas (2002) and Gurinder Chadha's crossover Bride and Prejudice (2004) have opened the world's eyes to the charms of Bollywood. And to the possibilities of co-productions. But Roshan says problems remain.

'Calling it a leap of faith would be appropriate,' says Roshan. 'With the first film, we used the same special effects team as used in Independence Day. In this film, the action is being co-ordinated here, we're working on getting the sound recorded in Australia and the same American team who worked with us earlier is keen to work on this film. The aim for any good production unit is to make the film better than the last and my father is taking a huge risk, but we're all hoping it'll be worth it in the end.'