South Korea has reported its investigation results on alleged illegal North Korean coal shipments into the South to the United Nations Security Council(UNSC). 

A diplomatic source at the UN said that South Korea submitted a letter on Monday detailing its probe results and measures taken against those involved in the illegal shipments in violation of UN sanctions. 

Last Friday, Seoul's customs office said that three South Korean firms imported North Korean coal and pig iron worth six-point-six billion won from Russia on seven occasions between April and October last year. The three importers and three entities were referred to the prosecution for their apparent violation of UN sanctions without detention.  

In response to the report, the UN sanctions committee on North Korea reportedly appreciated the Seoul government's cooperation with the international community and its commitment to the implementation of sanctions. 

Seoul's report on its probe results will be circulated among the members of the Security Council. Attention is being drawn to whether the UNSC will take its own measures against the ships used for the illegal shipments.