SINGAPORE - Two former Shell Eastern Petroleum employees linked to a case involving more than 300,000 tonnes of stolen gas oil worth over $200 million - the largest ever amount for such a case in Singapore - were jailed on Monday (July 5).

Former authorised gas safety tester Muhammad Ashraf Hamzah, who along with other colleagues misappropriated 55,321 tonnes of gas oil worth nearly US$25 million (S$33 million) between 2014 and 2016, was sentenced to 9½ years' jail.

The 39-year-old Singaporean received at least $700,000 through his participation in the conspiracy.

In January, he pleaded guilty in a district court to nine counts of criminal breach of trust involving gas oil worth more than US$18 million.

Nine other similar charges linked to the remaining amount were taken into consideration during sentencing.

Ashraf also admitted to one count of laundering a portion of his ill-gotten gains when he bought a car, a Volvo, for about $200,000 in 2017.

His former colleague, Sadagopan Premnath, 40, who worked as "either a fieldman or panel operator", was sentenced on Monday to six years and eight months' jail.

In December last year, the Indian national admitted to his role in misappropriating gas oil worth about US$36.1 million between 2017 and 2018.

Sadagopan received about US$150,000 from his involvement in the scheme.

The cases involving other alleged offenders including Muzaffar Ali Khan Muhamad Akram,40, Juandi Pungot, 44, and Abdul Latif Ibrahim, 63, are pending.

The oil heist took place at Shell Pulau Bukom, the company's largest petrochemical production and export centre in the Asia-Pacific region.

The court heard that some time in 2007, Juandi and Abdul Latif started a conspiracy to misappropriate gas oil from Shell.

Deputy Public Prosecutor Stephanie Chew told the court that they began to conduct "illegal loadings for the Anic 1 bunker ship", a vessel owned by Sentek Marine & Trading.

"Juandi and Latif were able to continue undetected, as they would tamper with the bunker meter. Emboldened by their success, Juandi and Latif continued to expand their criminal enterprise," she said.

The court heard that between 2008 and mid-2013, the pair expanded their illegal loadings to many other bunker ships, and recruited other colleagues, including Ashraf who was roped in no later than 2010.

Ashraf left the syndicate in 2016.

The court was told that Juandi recruited Sadagopan into the syndicate in mid-2017.

The DPP said that Muzaffar was recruited between late 2007 and early 2008.

A Shell representative alerted the police in August 2017 after the company detected the loss of fuel.

Anyone convicted of criminal breach of trust can be jailed for up to 15 years and fined.