The rich baritone voice is unmistakable and the tall, imposing figure and striking features cause heads to swivel as he walks through the hotel foyer. Apart from the addition of a silver-tinged beard, these features have changed little in the 40 years that Amitabh Bachchan has reigned supreme in the world of Indian cinema. He is still a fine figure of a man. Perhaps the voice is a little bit softer and the movements less vigorous, but that is to be expected after a 67th birthday, more than 100 Hindi-language movies and countless awards, plus spectacular failures in business and politics and a series of health scares.

Bachchan has been battered by life, but it doesn't show in his handsome face and he believes he has emerged from his troubles stronger and a happier man. He is back where he feels he should be - in front of the cameras. "Acting was my profession, but whenever there was an occasion to do something else I went in there. Some of them were failures. Well, most of them, actually, but I have continued with acting for 40 years," he says with an ironic smile. "Fortunately, there are still some people who want me to work with them. I am on the other side of the hill and I think the slide is very rapid once you are on the other side and you have to accept that. If there is other related activity then I am prepared to look into it, but I can't do production and I can't do direction, so I guess I will continue to act."

Bachchan is in the UAE to be honoured by the Dubai International Film Festival and to talk about his latest movie, Teen Patti, in which he stars with Sir Ben Kingsley. On Wednesday evening he was presented with a Lifetime Achievement Award, which makes him feel "very humble", coming as it does from a country other than India. "I am humbled to find myself recognised in a foreign country, but I look at it as recognition for my country and my cinema rather than an individual. The fact that it is an award from outside India and that the people of the Emirates are also conversant with our cinema and want to give it recognition is very laudable."

He holds legendary status in India and is mobbed wherever he goes. Although he dislikes the term Bollywood, he is the industry's most famous proponent, and topped a BBC poll 10 years ago that acclaimed him as the biggest star of the millennium ahead of Sir Laurence Olivier, Cary Grant and Charlie Chaplin. But he modestly plays all that down. "I don't believe in all these things. I'm just as common as everyone else. My profession puts me into a medium where you are made to do extraordinary things and when you do something extraordinary it's always very attractive, but that's it, nothing more." Anyone expecting to meet the angry young man or loveable rogue of his early movies such as Sholay and Coolie would be disappointed. Bachchan today carries an air of old world courtesy about him. Unfailingly polite and elegantly dressed in a dark pinstriped suit, red tie and fashionable black patent leather shoes, he stands up to greet people and answers questions thoughtfully but with an edge that is a little distant as opposed to aloof. Over the years, his enormous fame has meant that his every venture has attracted overwhelming interest, which is sometimes hard to bear.

His short-lived venture into Indian politics, for example, was a bruising experience. In the mid-1980s after the assassination of the prime minister Indira Gandhi, he was elected to parliament with a huge majority in his home city of Allahabad. He quickly became disillusioned, however, after being implicated by a newspaper in the Bofors arms scandal, which involved millions of rupees allegedly paid to politicians and officials in bribes for the import of weapons. Although he was cleared of any wrongdoing, he gave up his seat after three years, describing politics as a "cesspool".

A sharp edge creeps into his voice as he dismisses the idea of another foray into that world. "No, I will never go back. I have accepted that as a failure and I don't want to go back. I'm very happy to be doing what I'm doing." Another high-profile failure came the following decade, when he launched a company, Amitabh Bachchan Corporation Ltd, to produce and distribute films, products and services for the entertainment industry. The firm was the main sponsor of the 1996 Miss World show - Bachchan's daughter-in-law, Aishwarya Rai, was the winner of the pageant in 1994 - but although the show was a spectacular production, it lost millions and led to the collapse of ABCL the following year.

Bachchan could have declared the company bankrupt and simply walked away, but it is a tribute to the nature of the man that he spent the next decade working to pay off his debts to the last rupee. He says there were two main reasons for this. "We went into a lot of minuses and went into the red and people suggested bankruptcy was a very common phenomenon and you just close shop and you move on. But I just felt that all the people I owed money, or the company owed money to, were people from the industry or around the industry and if I was going to be working and living in the industry, I would have to face them at some point in my life and that would have been very embarrassing and awkward for me.

"But the other thing was that a company that bore my father's name I didn't want it to be looked upon negatively. And so I worked hard and paid back all the money to everyone that I owed and I'm very happy about that. And now we are free," he says. His father, Dr Harivansh Rai Bachchan, was a well-known Hindi poet and it is clear that family traditions play a central part in th actor's life. His wife is the actress Jaya Bhaduri and they have two children, a daughter, Shweta Nanda, who is married with two children, and a son, the actor Abhishek Bachchan, who is married to Rai.

"My wife, son, daughter-in-law and I all get up in the morning and go off in various directions with our respective make-up bags. We all live together and I have never really questioned it because that's part of our culture, that's how it is supposed to be and so it will be like that. I grew up wanting to immediately stand on my feet so that I could look after my parents. That was my aim in life and that is what we did. My parents lived with me and my children live with me and hopefully they will be equally concerned about me when I grow older and immobile."

Bachchan welcomes the changes in the Indian movie industry while defending the old ways of Bollywood with its singing and dancing and bright colours. That will never change, he believes. "Our cinema offers poetic justice in three hours. You walk away from an Indian cinema with a smile on your lips and dried tears on your cheeks. I don't like the term 'Bollywood', but any word that goes into the Oxford dictionary is there for eternity, so you can't do anything.

"At first we were looked upon very cynically by the West and criticised for our content because it was too fantasised, too escapist in nature. But what the West has to realise is that our cinema was made for the common man and the common man in India is very poor and has to struggle throughout the day to earn a living. "It would be terrible if, at the end of the day for his relaxation, he was to walk into a cinema paying for a ticket which is his entire salary for the day and see his own life being re-enacted. He wants to come and relax, he want to be driven away from this penury that he is subjected to. He wants escapism, to be transported into a world of wonderful scenes and colours and beautiful women and to hear good music and be able to travel to Switzerland or London or New York just by sitting in a theatre. So that was his fantasy world and we shouldn't take that away from him. He will never get the opportunity to see Oxford Street in London or Madison Square in New York or just walk the New York streets.

"For two hours he can escape and live in a world of fantasy and then go back a little satisfied." His new film, Teen Patti, to be released in February, is a departure from the normal Bollywood themes. Produced by the 30-year-old Ambika Hinduja, it tells the story of a mathematics professor who discovers a formula that enables him to predict the result of a card game. "I'm in the process of writing my thesis on probability and getting rejected by my seniors who are jealous of the fact that if I came up with the thesis, I would become somewhat superior to them. Therefore, they keep rejecting it.

"In my character's frustration, one day when he is fooling around with his computer he accidentally comes across a card game, called Teen Patti, which he plays and discovers to his great surprise that using his theory of probability he is able to crack the code and predict the opponents' cards in a poker game. He discloses the theory to his junior, who involves some of his students. His only fear is that it's all very well on paper but he needs to give it some practical use. They then go out to test it and it works. He is overjoyed but the others see ulterior motives. Then comes the greed and intrigue and he gets trapped in his own little world as the plot unfolds."

Bachchan believes that his Indian fans will respond well to Teen Patti. "I think they will want to see it because there is sufficient material which has drama and a message, and all our scriptures talk about greed and its ill effects. When you make a film like Teen Patti where there is a qualitative and quantity difference, they recognise it. So it may not necessarily have the usual song and dance, but it has a certain quality which fans want to identify with."

Working with Sir Ben Kingsley was "a delight". "Ben is an Oscar winner and a true professional. I spent a few days working in London in a rather upscale casino and it was a joy to be standing in front of a camera with him and living in his reflected glory." He particularly enjoyed working with a female producer and director, something that never happened in the early days. "We had two ladies in charge of the ship and it was wonderful to see the number of women in all areas of the production. I believe that women should be 50 per cent of representation in all walks of life. They are a very potent and important force and I've always believed that. I find them in all departments and that was unheard of at the start of my career."

Audiences in India have become more sophisticated in their expectations, he says, and a new generation of filmmakers has had to change and develop. "Modern directors are aggressive, determined and very conscious of what is going on in the rest of the world. They are also more open to discuss sensitive issues. "The other factor is that with the opening up of the economy and the rise in GDP, if you want to call it that, the common man is being exposed to things that are happening in other parts of the world almost simultaneously thanks to the communication boom, whether it is television, radio, the internet or other devices.

"As a result of economic progress and the rise in the middle-class fraternity in India, the quality of the information he receives is much better, too, so standards are forced higher. More than 350 million people have suddenly become richer with access to the most modern gadgetry. If they see something that isn't of good quality in their own cinema, they will reject it." Bachchan has embraced new technology and writes a daily blog for his fans. "It has given me a voice that can be heard and can't be corrupted or misrepresented."

It also enables him to correct such misrepresentations as happened with Slumdog Millionaire, when he appeared to criticise the movie for giving a one-sided impression of India. "I was misrepresented. I merely put two opinions of two respondents on my blog and they thought it was my opinion. I thought it was a wonderful film and we must respect the creative aspect of Danny Boyle. This was his perception and how he wanted to make that film and I thought it was fine and beautifully executed," he says.

There are echoes of his life in Slumdog, and part of his financial recovery involved hosting India's version of Who Wants to Be a Millionaire, called Kaun Banega Crorepati. The show was a massive hit and introduced Bachchan to a new audience. He says he has no idea what the future holds, but after several health scares, he is just glad to be alive and working. In 1982 while filming Coolie, he suffered a near fatal intestinal injury during the filming of a fight scene and spent months in hospital. He also suffers from the chronic progressive muscular disease myasthenia gravis and now exercises in the gym for one and a half hours every morning as well as maintaining a strict vegetarian diet.

"I keep having these episodes every other year. I hope there will be an end to it. Health is always going to be a problem, but I have survived some of the scares and hope I can keep away from them. It's important to look after your health and body. The profession demands it. I have put on a little weight and I need to get rid of it. It's a very physical profession whether it's your face or your body. You need to take care of it."

Film, however, is where he feels most comfortable. "I enjoy being in front of the camera. I don't look at my life and career in terms of goals that have to be reached. I'm grateful that there are still people who want to work with me. I haven't analysed very deeply what more I have to do with my life, although being satisfied is a curse."