'There's nothing to worry about now,' a spokesman told The Sunday Times.

'As of today, there have been no new cases.'

But as a precaution, the school's dining hall has been shut till further notice.

All meals will now be brought in from the caterer's central kitchen - outside the school's Woodlands campus - until the dining hall re-opens.

The Ministry of Health and National Environment Agency are also investigating what caused more than 100 students to fall ill.

The drama began at about 5pm on Thursday when students started complaining that they were vomiting or having diarrhoea.

The number swelled overnight, with a total of 113 cases as at 4pm on Friday.

This is believed to be the first large-scale case of students calling in sick since the Sports School opened in April 2004.

A parent, who is a doctor, helped screen the students and 18 of them were taken to a clinic in Woodlands and given medication.

Only one was granted medical leave and exempted from school and training for two days. None was hospitalised.

The spokesman added: 'The parents of all these students have been informed.

'Medication was also given to other students with milder symptoms when required.'

The school has 423 students across nine academies: golf, sailing, swimming, track and field, bowling, badminton, table tennis, netball and soccer.

Asian Games gold medallists Tao Li (swimming) and Sherman Cheng (sailing), and national triple jump record holder Stefan Tseng said yesterday that they were not among those who had taken ill.

Tao Li said: 'I carried on training today along with all the other swimmers. Everything is all right.'

The episode has not affected school activities, and classes and training will carry on as usual.

A senior school official said: 'We do not know the cause of the situation pending the investigation.

'It could be anything from the water supply, the food or a virus.'