In November, the two half-French, half-Malay children took the International General Certificate of Secondary Education in maths for 16-year-olds. The results are due next Monday.

They have been tutored by Horatio Boedihardjo, a 20-year-old maths genius from Hong Kong, who, when only 18, obtained first-class honours in a bachelor's degree in mathematics at Oxford, then leapfrogged to pursue a doctorate in maths.

Rosalind Corlin quit her job in finance when her children were two years old to hone in on their care. She wrote to Horatio four years ago to ask him to take them under his wing.

'I want to take an active approach to parenting,' said Corlin, whose husband, Remi Corlin, heads a US medical technology company.

The controversial Chua, author of the new best-seller Battle Hymn of the Tiger Mother, rose to instant fame by making an impassioned argument in favour of a heavily disciplined, demanding approach to motherhood that she characterises as typically Chinese.

Corlin agrees with the Chua approach. 'What she does seems extreme,' Corlin said, 'but she's right in the sense that self-discipline is important. Kids themselves don't really want to do it. They are not happy having to wake up at 5.30am. Letting them do what they want now is not really a good approach.'

Corlin endorses sport. 'Sport is extremely important. It's an important part of our lives. They do it every day. Sport allows them to play with their friends. It's a way of relaxing for them.'

The twins, who speak fluent French, Putonghua and English, practise six mornings a week at the Ladies Recreation Club in Mid-Levels under former Singaporean national swimming team coach John Dempsey.

Estephe admitted it was hard to get up so early in the morning, especially in the cold weather. He loves books by theoretical physicist Stephen Hawking and Chinese writer Lu Xun and said it could be pretty tiring sometimes having to spend the whole day in the pool during competitions.

But this determination has reaped a basketful of trophies - literally. 'They are all in a lump,' his mother said.

Sixth-graders at the French International School, the twins are straight-A students. They do not play video games. They do not watch television. 'They don't know what TV is,' their mother said.

'I take pleasure in doing sports,' said Estephe, who also plays rugby. 'I want to be successful and travel around the world and see how other people live. I want to go to study at Oxford like Horatio.'

Perrine said she loves reading Journey to the West and enjoys learning chess from her father and Finnish national chess coach Kalle Kiik.

The Corlins have lived in Hong Kong for six years, moving here from Switzerland.

Rosalind Corlin said childhood was a critical time. 'If they want to achieve something, they need to make an effort.'