Its second batch of IB students also saw nine having a perfect score of 45, according to results released on Tuesday.

The average score of 40.1 out of 45 was also an improvement over last year's average of 39.4 points.

The regional director of the IB Organisation in the Asia Pacific region, Ms Judith Guy, who described last year's results as 'very impressive', said this year's scores were "exceptional."

A total of 407 students took the IB exam last November, 50 more than in 2007. Of these, 98.75 of them graduated with a diploma and one student with a certificate.

ACS(I) is the first Singapore school to offer the IB in place of the A levels. The new School of the Arts will also offer it.

The IB programme is considered by educators to be more broad-based than the A levels, with all students taking six subjects and Theory of Knowledge, a course that combines philosophy, religion and logical reasoning.

Students also do a research project, write a 4,000-word essay on it, and have to clock 150 hours of service to the community over two years.