A North Korean ship carrying a shipment of coal intended for the Penang Port was stopped by Malaysian officials on Wednesday in order to be boarded and inspected due to suspicion of violating United Nations sanctions on the reclusive Asian state.

Malaysia, which has historically been one of the few friendly nations to North Korea, has seen their relationship sour in recent weeks, following the assassination of Kim Jong Un’s half-brother at the Kuala Lumpur International Airport.  The investigation into Kim Jong Nam’s murder led officials to determine he had been poisoned by a banned chemical agent known as VX; a material that would be difficult to procure outside of a state-run laboratory.  Malaysian investigators have repeatedly made attempts to speak to North Koreans who were implicated in the attack, but have been barred from doing so by North Korean officials.  Many take North Korea’s aggressive efforts to curb the investigation as evidence that the assassination was ordered by none other than Kim Jong Un himself.

Now, it would seem that Malaysia has chosen to take a harder line on North Korea’s coal exports – which are heavily regulated by U.N. sanctions as one of North Korea’s primary exports, and source of cash to fund their fledgling nuclear and ballistic missile programs that have put many around the globe on edge over the past year.

The ship, called the Kum Ya but previously named Lucky Star 7, was carrying a load of 6,300 metric tons of anthracite coal and twenty crew members when it was stopped by Malaysian officials before it could dock, and boarded by an inspection team.  The ship was immediately cordoned off and more inspectors were called in to verify the cargo on board was indeed what it was supposed to be.

“Minerals and Geoscience Department officials were then called to inspect the cargo on board. The department officers were told to confirm it was indeed coal on board,” a port worker that wished to remain anonymous said.

The coal was eventually permitted to be unloaded, and has not been confiscated by authorities, indicating that the shipment was indeed legitimate, but more importantly, this event marks what could be a significant shift in the relationship between North Korea and Malaysia – which could be traumatic for the North Korean economy, and Kim Jong Un’s nuclear plans.

“Many North Korean ships call on our ports and we never had problems. Just over the recent months, there have been problems,” the port worker told Reuters. “We have never received directives to stop North Korean ships before.”

On February 26th, China chose to halt all coal imports from North Korea as a result of growing tensions in the region regarding the country’s ballistic missile tests, and efforts to establish a ballistic platform for nuclear weapons.  China, traditionally North Korea’s largest importer, made a significant dent in the funding flowing into Kim’s pockets, making his relationship with Malaysia that much more important to the overall financial stability of the nation’s government.