South Korea's Foreign Ministry on Wednesday highlighted more measures Seoul has been taking to block illegal imports of North Korean coal.
The ministry stated that it actually reported its interception of the Togo-flagged vessel 'Talent Ace' in January, and the move was subsequently submitted to the United Nations Security Council Sanctions Committee in March due to suspicions that the ship was transporting coal from the North.
But the issue rose to the fore this week after media reports claimed that around 9,000 tons of North Korean coal were shipped to ports in the South last October, despite a UN prohibition aimed at curbing Pyongyang's development of nuclear weapons.
The South Korean government responded by insisting it is investigating the matter, including who was responsible for bringing in the coal and where it ended up.
"In cooperation with the international community, the [Seoul] government has been faithfully implementing UN Security Council sanctions against the North," a Foreign Ministry official was quoted as saying by local news agency Yonhap.
Seoul has reportedly also taken action against two other vessels believed to have been involved in prohibited activities related to North Korea.
South Korea's official stance is that it remains committed to sanctions against the North until the latter's complete denuclearization, but critics have suggested Seoul's handling of Pyongyang is softening amid an ongoing improvement in ties.
By Alex Jensen in Seoul