South Korean lawmaker Yoo Ki-june on Tuesday called on the government to take action against a ship suspected of violating United Nations sanctions by transporting coal from North Korea.
The Belize-flagged vessel is apparently at a South Korean port but is scheduled to leave on Wednesday night.
It is claimed the ship arrived in Pohang from Nakhodka in Russia on Saturday along with 5,100 tons of North Korean coal, which would be banned under a UN resolution passed last year in response to Pyongyang's repeated nuclear provocations.
Yoo, a conservative politician, said the South's liberal government "should immediately implement necessary steps under the U.N. sanctions," according to local news agency Yonhap.
He added that the vessel in question has been to South Korea 20 times since last October.
Following criticism that Seoul might have been turning a blind eye in order to gain political capital with Pyongyang, an official from Seoul's Foreign Ministry revealed this week that nine possible North Korean coal shipments are already being investigated.
The South is obligated to seize and probe any vessel suspected of violating sanctions, while the United States has made it clear it will take a dim view of any nation enabling North Korea to get around denuclearization efforts.
By Alex Jensen in Seoul