The name of a North Korean arms exporter was reportedly included in a catalog for North Korea’s CHT-02D torpedo that South Korea’s military and civic joint probe team said caused the sinking of the “Cheonan” naval ship in March.

A military source said the features and blueprint of the torpedo are included in the promotional catalog that Seoul has acquired. The source added that the catalog included the name of a North Korean arms exporter, the “Cheong Song Association.”

The firm is one of the North Korean arms exporters that has been included on a list submitted to the United Nations by U.N. experts who have been monitoring developments in the implementation of sanctions against the communist state.