SINGAPORE - A cargo officer was working on board a Singapore-flagged tanker in late October 2018 when it unlawfully transferred oil to a vessel believed to be North Korean-flagged.

This was done even though United Nations Security Council (UNSC) resolutions prohibit such transactions.

The cargo officer, Jeremy Koh Renfeng, and two other Singaporean men then worked together to present a false narrative on the movement of the Singapore-registered MT Sea Tanker II by falsifying its logbooks, which were subsequently presented to the authorities.

Koh, 40, was jailed for six months on Monday after he pleaded guilty to two counts of intentionally obstructing the course of justice.

His two co-conspirators were dealt with in court in February.

Ong Chou Hong, 33, who was an assistant marine superintendent at the time of the offences, was sentenced to nine months’ jail.

Benny Tan Chun Kiat, 47, who was then also a cargo officer, was ordered to spend six months behind bars.

The offences came to light when investigators checked Koh’s mobile phone after they received information about the unlawful transaction and found deleted images linked to it.

The prosecution said that as a member state of the UN, Singapore is obliged to implement the UNSC sanctions and its respective resolutions on North Korea to counter its nuclear weapons programme.

At the time of the offences, the three men were working for Sea Hub Tankers, which owned and operated MT Sea Tanker II.

According to images of items taken from Koh’s mobile phone, MT Sea Tanker II had transferred oil to a vessel called MT An San I – believed to be North Korean-flagged – in October 2018.

The report was signed off by a chief officer from one “Ansan Shipping Company”, believed to be a North Korean shipping company.

This transfer to MT An San I was not recorded in MT Sea Tanker II’s official logbook.

In late 2018, the Singapore authorities received information alleging that MT Sea Tanker II had engaged in a ship-to-ship transfer with a North Korean-flagged vessel.

On Nov 5, 2018, the Maritime and Port Authority requested Sea Hub Tankers to present documents including MT Sea Tanker II’s official logbook.

Some time between Nov 5 and Dec 6, 2018, Ong and Tan gave instructions to Koh, who was then on board the vessel, that the records in MT Sea Tanker II’s official logbook had to be rewritten.

According to court documents, the trio agreed on a purported timeline for the movement of MT Sea Tanker II.

In November 2018, Ong informed Koh that Tan will be bringing a new computer processing unit (CPU) to the ship, and instructed Koh to destroy the old CPU containing records pertaining to MT Sea Tanker II’s activities.

Deputy Public Prosecutor David Koh said: “Later... Koh informed Ong that the crew had backed up their files, and that he would be throwing the (old) CPU into the sea. Ong warned him that he should not let others see him throwing the CPU into the sea.”

Koh later dismantled the CPU and sent Ong a picture to show that he had done so. After that, Koh threw the dismantled parts into the sea.

The truth emerged after investigators retrieved images from Koh’s mobile phone.

On Monday, defence lawyer Tang Chong Jun told the court that Koh’s culpability was lower than that of Ong’s and Tan’s, stressing that his client was the pair’s subordinate.

Mr Tang also said that Koh had derived no monetary benefit for helping the pair.