North Korea smuggled state-of-the-art measuring equipment used in long-range rockets and missile launchers from China in April.

Citing an unnamed source, a Seoul-based daily said a Chinese company forged documents to illegally export the machinery to North Korea, an activity banned under UN Security Council Resolution 1874.

Pyongyang is also believed to have imported prohibited materials related to weapons of mass destruction as well as luxury goods through routes in China, Japan, Mongolia and Russia.

In June two Japanese nationals were arrested by local authorities for attempting to export hydraulic shovels to the North, as a substitute for a missile launcher.

Officials in Seoul have informed Washington of the latest developments.