The Singaporean foreign ministry says a former counselor at the country's embassy in Japan who is suspected of secretly filming a naked teenage boy at a public bath in Tokyo has already returned to Singapore.

Investigative sources say the 55-year-old diplomat allegedly took video of the 13-year-old covertly with a smartphone in a bathhouse changing room in February. The man was still working at the embassy at that time.

The Tokyo Metropolitan Police Department is investigating the case under laws banning child pornography and others.

Singapore's foreign ministry issued a statement through its embassy in Japan after the allegations came to light.

The statement says the ministry had not previously been informed of the incident by the Japanese authorities.

It also says, "The staff in question had completed his tour of duty as scheduled and returned to Singapore in mid-April."

The ministry also says the official has been suspended from duty to assist with the investigation. It expressed its intention to cooperate with the Japanese authorities.

The statement also says the ministry would be prepared to waive diplomatic immunity for the man if the allegations prove to be true.