South Korea's Customs Service revealed at a briefing on Friday that North Korean coal and pig iron have, in fact, been brought into the country illegally.
Three South Korean firms were found to have broken the law in 7 of the 9 cases.
Most of them involved the fabrication of documents about the goods' origin.
"After the UN Security Council banned the trading of North Korean coal, the suspects transshiped the North Korean product at a Russian port onto a vessel with a third country's flag and forged documents to make it look like the goods were from Russia."
Inspections of Russian coal, in particular, have gotten tougher because of the sanctions, so in one case the company said falsely that the coal was of a type that doesn't require a certificate of origin at all.
Between April and October last year, they brought in a total of 35-thousand tons of North Korean coal and pig iron, worth some 6.6 billion won, or about 5.8 million U.S. dollars.
Most of the coal had been acquired by the suspects as commission for selling North Korean coal to third-party countries.
It's thought the reason they did it was because coal from the North is so cheap.
This is a clear violation of UN Security Council resolution 23-71, which stipulates that North Korea shall not supply, sell or transfer directly or indirectly coal, iron or iron ore, and that all UN member states shall prohibit the procurement of such material from the North.
The Korea Customs Service said it will refer the firms and their representatives to the prosecution.
And the ships that brought in the coal, including Shinning Rich and the Jin Long, will be reported to the Security Council committee on North Korea sanctions, but its not clear whether the ships will face sanctions themselves.
Either way, the South Korean government said it will ban them from its ports.
As for a local company that bought and used the coal, the customs service said it's likely to be exempt from the United States' secondary boycott because it could not have known the coal's origin.
Lee Ji-won, Arirang News.