SINGAPORE - Two men, who were originally handed 5½ years' jail for extracting more than $2 million in bribes from a flour distributor, had their jail terms cut on Wednesday (Dec 2), following their appeal to the High Court.

Katsutoshi Ishibe, 55, and Takaaki Masui, 57, were each sentenced to three years, seven months and three weeks' jail as well as a fine of $200,944.

The two Japanese men were also each ordered to pay a penalty of more than $1 million, a sum equal to the amount of bribes they had received.

They will have to serve an additional one year's jail if they cannot pay the fine and the penalty.

Justice Chan Seng Onn said in his 199-page judgment that this was "one of the most egregious cases of purely private sector corruption in Singapore".

However, he determined that the original sentences were manifestly excessive, after he set out a sentencing framework for cases of corruption involving private sector agents performing purely commercial functions.

Under the law, the offence carries a fine of up to $100,000 or jail of up to five years, or both.

On Wednesday, Justice Chan, who has previously issued sentencing frameworks with the help of graphs, gave a presentation in court for nearly two hours, using conceptual diagrams and 3D models to explain his methodology.

His framework involved a modified version of the typical matrix which sets out nine sentencing ranges depending on three levels of harm and three levels of culpability.

Unlike the traditional nine-grid box, his matrix included a "towards infinity" section to account for extreme levels of harm and culpability.

In his written judgment, Justice Chan noted that the current case fell within a category of cases for which there are few available precedents.

In sentencing the pair in 2018, a district judge adopted a sentencing framework that set out four bands of starting point sentences based on the number of offence-specific factors.

Masui and Ishibe were each convicted of 28 charges of corruption for obtaining bribes from Singaporean Koh Pee Chiang between 2004 and 2007.

The two men were seconded to work for the Singapore subsidiary of trading firm Nissho Iwai Corporation. Following a merger in April 2004, the subsidiary was renamed Sojitz Asia, where Masui was general manager and Ishibe was manager.

Mr Koh was the sole proprietor of Chia Lee & Co, a longstanding distributor of edible flour for the duo's employer.

In 2002, the duo told Mr Koh to enter the industrial flour business.

The pair devised a profit-sharing arrangement pertaining to the industrial flour business to extract bribes from Mr Koh in return for them continuing to "support and protect" his edible flour business.

Mr Koh was allowed to keep US$3 per tonne of industrial flour while the remaining US$20 was split between Masui and Ishibe.

Over the years, Mr Koh's share remained constant, even though profits increased to as much as US$60 per tonne.

When he voiced concerns about the scheme, the duo threatened to withdraw their support and protection for his edible flour business.

As a result, Mr Koh felt he had no choice but to continue paying the two men.

After the verdict, Masui's lawyer, Mr Nicolas Tang, sought one week's time for the duo to consider whether they wished to refer the case to the Court of Appeal.

Ishibe's lawyer, Mr Sunil Sudheesan, said Mr Tang will take over, should the matter go further.

Justice Chan said the pair have to start serving their jail terms on Dec 10 if they do not file the court papers by Dec 9.