A cleaning supervisor duped his four female workers and a site security manager into handing over a total of $542,930, purportedly as investments with the bank where they were deployed.

Goo Pau Hin, 52, who faced 94 charges, had admitted to 20 counts of cheating his four cleaners, aged 51 to 78, and the 36-year-old security manager, of between $10,000 and $330,950 each between 2010 and 2013. The remaining charges were considered during his sentencing on Tuesday.

He deceived them into believing that he would invest their money with the Bank of America Merrill Lynch.

He was sentenced to six years' corrective training, a regime for repeat offenders with no remission for good behaviour.

The court heard that Goo, who was employed by Ramky Cleaning Company and deployed to work at the bank at HarbourFront Place, began gambling heavily in 2008. He spent most of his salary on gambling and even borrowed money from his workers to fund his gambling activities.

In 2010, he came up with an idea to cheat his elderly female workers of money.

He asked them if they were keen to invest their savings with the bank.

He claimed the bank allowed staff, including cleaners, to invest money to earn attractive interest rates as they had worked hard and the bosses of the bank took pity on them. He also lied to them he had invested in the bank and had received high dividend payouts.

To bolster his false representation and to add credibility to his claim, he asked for a photocopy of their identification cards and bank account details.

To maintain his deception, he handed them bank statement slips with fictitious details and account numbers as proof of their deposits; paying "dividends" or "interest" periodically to induce them to make more investments.

The court heard that the total amount he gave to his victims in the form of "dividends" was $97,160.

Deputy Public Prosecutor Eunice Lim highlighted several aggravating factors to ask for a stiff sentence. She said there was considerable planning and pre-meditation as Goo perpetrated the scam to cheat multiple victims over three years. He avoided detection by providing proof of deposits, which were in fact actual bank statement slips, to give a veneer of authenticity, and paying so-called "dividends".

"The accused systematically targeted vulnerable, elderly and female victims who trusted in financial institutions, such as the bank, and cheated them of their life savings and security for old age," she added.

Goo has cheating-related convictions in 1992, 1994 and 2004.