Despite being caught in England for possessing child pornography, former Ministry of Education (MOE) scholar Jonathan Wong taught in a secondary school after he returned to Singapore, local media reported.
Wong, 23, was arrested in March, but MOE said that his offence only came to light after he was charged in British court in November, Channel News Asia reported.
The history major at the University of York did a month-long teaching attachment in July at a secondary school in the West of Singapore after his return.
According to MOE, neither Wong nor his university had informed the ministry of his March arrest or that he was under police investigation when he returned for his school attachment.
University of York spokesman David Garner said the university was also not informed by the British police of Jonathan Wong's arrest or of the subsequent charges.
He said the university knew of the charges for the first time when Wong appeared before the York Crown Court on November 15.
Online reports said that Wong, who taught history and literature during his attachment, worked closely with the students.
A teacher at the school - not named by the reports - said that nothing was amiss and Wong behaved like any other teacher during his stint.