They were employed by SMRT Trains, but are accused of secretly having interests in two companies that were bidding for contracts from the rail operator.
Over a period spanning almost five years, they allegedly managed to dupe SMRT into awarding 28 contracts valued at almost $10 million to these two companies.
Yesterday, three current and former employees of SMRT Trains were hauled to court over cheating charges.
The men had allegedly concealed their interest in the two companies - building and infrastructure construction firm Enovation Industries (EI) and construction company Enovation Technologies (ET) - which scooped up contracts worth about $9.8 million from SMRT.
Charge sheets show that in November 2007, SMRT Trains' former assistant engineer Zakaria Mohamed Shariff, 59, and former manager Jamalludin Jumari, 61, allegedly teamed up with Akbar Ali Tambishahib, 60, a company director, to win an SMRT contract for EI.
EI won two more SMRT contracts through to July 2008. The total value of its SMRT contracts was more than $87,000.
From January 2009, the charge sheets show, these three were joined by line manager Zulkifli Marwi, 52, and, on 24 occasions, they managed to win SMRT contracts valued at about $5.9 million in total for ET.
It is an offence for employees to cheat their employers for their own personal gains, and they will have to bear the full brunt of the law.
CORRUPT PRACTICES INVESTIGATION BUREAU, in a statement yesterday.
Akbar was a director of ET, and the last instance in which the four men are accused of conspiring to win an SMRT contract was in July 2011.
In July 2012, ET is said to have won purchase orders worth more than $3.8 million from SMRT, but Zulkifli has not been named as part of this.
Akbar, Zakaria and Zulkifli were each offered bail of $100,000 yesterday.
Deputy Public Prosecutor Sanjiv Vaswani said no bail was offered to Jamalludin as he had been on the run since May 2013 and was arrested in Malaysia only on Thursday.
In a statement yesterday, Singapore's Corrupt Practices Investigation Bureau (CPIB) said it had worked closely with the Malaysian Anti-Corruption Commission on the case.
CPIB added: "It is an offence for employees to cheat their employers for their own personal gains, and they will have to bear the full brunt of the law.
"The Corrupt Practices Investigation Bureau takes a serious view of any corrupt practices and will not hesitate to take action against any party involved in such acts."
Zulkifli is represented by lawyer Patrick Fernandez, while the other three men told the court that they intend to engage lawyers.
All four men will be back in court on Jan 15.
Offenders convicted of cheating can be jailed for up to 10 years and fined on each charge.