"They do not want anybody on their ships," he said. "Whether it's carrying melons or nuclear technology, the North Koreans would act pretty much the same way."
A history of weapons shipments
This isn't the first time North Korea has been linked to shipping suspected of transporting weapons materials.
In 2011, the U.S. Navy tried -- and failed -- to gain permission to board a ship in the South China Sea suspected of carrying illicit weapons technology to Myanmar, the Pentagon said. The Belize-flagged MV Light was believed to have been manned by a North Korean crew, the Pentagon said. Under U.S. Navy surveillance, the vessel eventually turned around and headed to North Korea.
In 2007, the Pentagon confirmed that several shipments of suspected weapons technology had left North Korea destined for Syria. The Pentagon said some of the material was believed to have been high-grade metals that could be used to build missiles or solid-fuel rockets.
CNN reported in 2011 that an unpublished U.N. report claimed North Korea was trading banned weapons technology with several countries, including Iran.