A senior Deutsche Bank executive met four men in Singapore and allegedly shared with them information promoting child sex activities in the Philippines.

However, Singapore permanent resident Michael Frank Hartung, 46, was unaware they were undercover police officers and he was later arrested, a court heard yesterday.

The German national, who is no longer an employee of the bank, appeared in court on the first day of his trial to face two charges of distributing information aimed at promoting commercial sex with minors.

Deputy Public Prosecutor Marshall Lim said that in April 2015, Singapore police received information that Hartung was suspected of being involved in "deviant sexual activities".

DPP Lim told District Judge Ng Cheng Thiam: "Police thus began to plan an undercover operation to conduct further in-depth investigations into the accused."

The identities of the four policemen cannot be revealed due to a gag order. One of them, an assistant superintendent at the Criminal Investigation Department, began communicating with Hartung through the Yahoo online messaging service in June 2015.

Using "Jackson Fong" as his pseudonym, the officer asked Hartung to plan an overseas trip for him and his friends, said the prosecutor.

DPP Lim said the assistant superintendent also told Hartung he would like to have sex with young virgin girls and the German indicated he was able to plan the trip.

The assistant superintendent and another undercover policeman, who is a superintendent, met Hartung at a Raffles City Shopping Centre cafe on Sept 26, 2015, the court heard.

DPP Lim said: "At that meeting, the accused distributed information... on engaging in child sex in the Philippines, discussed trip and payment details, and agreed that a trip to the Philippines be planned between Oct 15 and 18, 2015."

Hartung did not contact the assistant superintendent after this meeting to finalise plans for the trip.

Police then conducted a second undercover operation, the court heard. Two other police officers, who called themselves Paul and Frank, met Hartung at a Mackenzie Road bar near Little India on April 15, 2016.

Hartung allegedly distributed to the pair information on child sex activities in the Philippines, including prices they were expected to pay for such services.

However, he did not contact them to finalise plans after this meeting, said DPP Lim.

Hartung is out on bail of $15,000. His trial resumes today.

Note: This story has been edited for clarity.