The principal of a top Singapore high school was Thursday removed from his post and being investigated by the anti-corruption bureau, authorities told AFP, in the latest such scandal to hit the city-state.

Former headmaster of River Valley High School Steven Koh Yong Chiah, 58, was replaced "with effect from 20 December 2012", the education ministry said in a statement emailed to AFP.

It said Koh had been redeployed while the investigation was underway.

"The Ministry of Education has been informed by the Corrupt Practices Investigation Bureau that Mr Steven Koh Yong Chiah, principal of River Valley High School, is assisting in its investigation," the statement read.

"As investigations are ongoing, we are unable to comment further on the case," it said.

Corruption scandals have this year claimed the scalps of top officials in Singapore, with an ex-top policeman and former civil defence chief currently facing sex-for-favours charges in court.

A law professor in a local university has also been accused by authorities of awarding favorable grades to one of his female students in exchange for sex and gifts.

Large-scale graft cases are rare in Singapore, a thriving global financial centre and business hub which enjoys a reputation for being the least corrupt country in Asia.

It pays its civil servants some of the highest government salaries in the world as a deterrent to corruption.