The US cited a ship already under UN port ban and its husband and wife owners for allegedly sneaking petroleum into North Korea.

The 6,031-dwt Shang Yuan Bao (built 1982) is accused of having twice sailed into international waters to transfer a total of 1.7 million liters of petroleum product to the North Korea-flagged 2,250-dwt Paek Ma (built 1993) and 817-dwt Myong Ryu 1 (built 2012) last year.

The Treasury Department's Office of Foreign Assets Control (OFAC) said the cargo was later discharged at Nampo, a port city southwest of Pyongyang. Both ships were already on the organization's specially designated nationals list.

"Shipping companies trading with North Korea are exposing themselves to significant sanctions risk, despite the deceptive practices they try to employ," said Treasury undersecretary Sigal Mandelker.

In addition to the Panamanian-flagged Shang Yuan Bao — which was hit with a UN port entry ban in October 2018 for the same transfers — Hong Kong-based Jui Chen Shipping Company and Taiwanese Jui Pang Shipping Company and Jui Zong Ship Management were added to the specially designated nationals list.

All three allegedly have interest in the ship.

Additionally, Taiwanese nationals Huang Wang Ken and wife Chen Mei Hsiang were listed. OFAC said Huang was the chief executive of Jui Peng and Chen was a director there, along with the sole owner of Jui Zong, the ship's owner according to Clarksons.

Huang allegedly worked with "several other individuals" to ship the petroleum, which was reportedly set for the Phillippines, to North Korea.

Once added to the list, individuals and companies have their US assets blocked and are prohibited from doing business in the US.

The US is reportedly paying much closer attention to the shipping industry as of late, with sources telling TradeWinds officials are using automatic identification systems to monitor ships.

A number for Jui Zong Ship Management obtained by TradeWinds appears to be disconnected.