ONE moment he is the legendary chief inspector of police, the next a gangster from Temple Street with a heart of gold; his voice can be heard crooning out ballads on practically every street corner in Hongkong. This is the Andy Lau Tak-wah the public sees, hears and loves - the actor, the singer, the superstar. But for all the love songs, the lead parts, the adulation, there is one important role the public knows nothing about. Lau, 31, is the ''father'' of 17 children from poor countries all over the world. From India and Ghana, to Mexico, Bangladesh and Indonesia, there are boys and girls who have Lau to thank for their health, education and sometimes the food on the table. Most of them have not met him, and all have no idea he is one of the biggest stars in Southeast Asia. ''Sponsoring the children was initially just a gesture to help others, but once you meet the children you have been supporting it is an entirely different feeling,'' Lau said. While his adoring fans love to shower him with affection, there is nothing that Lau loves more than to lavish love and affection on his ''family''. He was choked with emotion as he described his feelings after his March meeting with one of his ''children'' in Indonesia. ''I was very, very happy. Happy beyond words,'' he said, still amazed at his reaction. ''She felt like my own fresh and blood. There was an invisible bond when I saw the girl.'' The two-day ''father and daughter union'' changed Lau's perspective about helping the needy. ''The initial mentality I had about the children is that I can help them. It was not anything particularly special. ''But until I had the chance to go to Indonesia and meet the little girl I am sponsoring, I did not even know what type of life she had. ''But what I saw was the kind of life that people should not have at all. For instance, the hygiene standards in their homes - and there should be a school for the children.'' Lau said even though 10-year-old Nina's parents were still alive, they were very poor. ''Some kids that you adopt, you never see them and they have no idea what you look like either. But then, they know that there is someone out there making a concerted effort to help them. The effort on our part is possibly very, very small. ''Before I sponsored Nina or the other children, I never thought it was any big deal. Just merely forking out, what, say $180 per month for each child? ''But once you actually come into contact with the person you have been helping, there is an immense happiness. You see that the effort has been well worth it. I found myself wanting to do more.'' Before meeting Nina, Lau had 12 children under his wing. He immediately sponsored five more. Unlike his carefully planned career, his involvement with the children began accidentally when he did some work with the charity World Vision. ''It was just a coincidence,'' Lau said. ''The first time was when World Vision and my fan club came together to raise funds by selling Christmas cards. ''From the people at World Vision, I came to know the agency better and what they do.'' World Vision's media and promotion head, Ms Alice Kwong Lai-kit, said Lau sponsored more children than any other artist. ''I think this came from within his heart,'' she said. ''He is doing something to help. He is not just saying it. ''By sponsoring the children, he is bringing hope and at the same time caring for them. It is not a one-off situation, but rather a long-term commitment.'' Lau, so used to the limelight, likes to downplay his role with World Vision. ''In my own capacity, and within my ability, I am willing to do whatever I can to help those in need.'' Lau manages to squeeze charity work into his tight schedule. A well-known workaholic, he is filming a scientific fantasy film called Super Street Fighters. ''In this film, there will be a good mix of modern technological and special effects,'' Lau said. ''The storyline is very simple. It is about the year 2000, and what will happen to the human race. In a certain place at that time, there emerged a crisis. The only person who could reverse a disastrous ending was controlled by the evil forces. ''The story is about how we have to travel back in time to find the person, when he was young, and teach him the right values all over again to save the future. ''I am the one responsible for travelling back in time to look for the person.'' . Although he plays heroic roles in most of his films, Lau said there was no one image which he felt his audience strongly identified him with. ''I want very much to be an all-round artist.'' He acknowledged he was an ''idol actor''. ''This is one of the aspects of my all-round image.'' Between filming schedules, Lau is busy belting out love songs. ''In every one of my albums, there is a song with the intention to encourage people. But to meet the market's taste, I have to have more commercial offerings.'' Lau said singing was a passion developed as a youth but he had a late start despite entering the business as a television artist in 1980. ''I only went professional in 1986 with the first album. It was more difficult to enter the market then. There were fewer avenues.'' Like the advancement in sound engineering of recording studios and filming techniques, Lau's career has gone from strength to strength. ''In Hongkong, for an actor to become a singer, the acceptance to come from the audience is slower. I don't know why,'' he said. ''But I think they have accepted me. If not, I would not be where I am today.'' The Hongkong audience knows Lau always strives for the best results. ''I always aim to achieve above the average standard, to do my best,'' he said. His 17 adopted children would agree. Do you want to be like Andy Lau and help poor children lead a better life? All it takes is $180 a month and each sponsor gets a picture of the child and an annual progress report. You will be in good company. Other artists who have sponsored children include Jacky Cheung Hok-yau and Cally Kwong Mei-wan. For more information, call WorldVision's hotline on 394-4123.