SINGAPORE - Not only did an Immigration and Checkpoints Authority (ICA) officer use his work-issued phone to alert three women from China working illegally here of impending raids, he texted them for massages as well.

Staff Sergeant Chin Peng Sum, 51, was found out when one of the women was arrested by the police for vice activities on May 31 last year, and his messages to her were found on her phone.

On Friday (Dec 28), Chin pleaded guilty to corruption charges and breaching the Official Secrets Act. He will be sentenced on Jan 2 next year.

Chin, who has been with ICA since February 1998, has been interdicted from service since June 15, 2017.

Deputy Public Prosecutor Loh Hui-Min told the court that while conducting operations to arrest immigration offenders, Chin met Zhu Shirong, Wang Chenghong and Tang Yuanyuan, some time between end-2016 and early last year.

The trio had been arrested for various immigration offences and were on Special Passes pending the conclusion of their cases.

Chin told them he could have their Special Passes extended and claimed this would let them remain in Singapore after the conclusion of their matters.

Some time last year, he contacted Zhu for a massage, hoping to get a discount for her services. Zhu agreed and they met at her residence in Geylang.

He did this although he knew he was not allowed to approach alleged immigration offenders for such services.

They had sex after the massage and Chin offered to pay her but Zhu rejected it.

About a month later, he contacted her for a massage and sex again, this time at her residence in Jurong West.

Chin also made the same requests of Wang, and received services for free on two separate occasions.

In his role, Chin received information from his superiors about impending raids conducted by ICA and other enforcement agencies.

On three occasions, he tipped the women off so they could avoid getting caught.

He knew they were liable for other offences and wanted to prevent their apprehension by the authorities.

But when Zhu was arrested on May 31 last year, a search through the contents of her handphone uncovered messages from Chin with information about impending raids and requests for massage services.

The ICA was alerted and Chin was called up for an interview by his management, during which he was informed that investigations against him would commence.

After the interview, Chin instructed Wang to delete all incriminatory WeChat messages between them.

He also deleted messages exchanged between him and the three women on his work-issued phone.

An ICA spokesman said the authority takes a serious view of errant officers.

"ICA officers are expected to discharge their duties professionally and maintain a high standard of integrity."

"Officers who break the law will be dealt with, in accordance with the law."

When the case was detected through ICA's internal checks and investigations, the authority reported it to the Corrupt Practices Investigation Bureau.

"Following the officer's conviction in court, we will commence civil service disciplinary proceedings against him with a view to dismiss him from service," added the spokesman.