Five companies in five countries were involved in a complex process of cargo laundering for a shipment of North Korean arms that was confiscated at Bangkok's Don Mueang Airport last month, according to media reports.

Efforts to track the cargo were complicated by the involvement of a Kazakh arms dealer and his wife who handled the arms through a ghost company, AP said Tuesday.

Thai police discovered 40 tons of North Korean arms including multiple rocket launchers, 40 surface-to-air missiles, and hundreds of rocket-propelled grenades worth an estimated US$18 million on an Ilyushin cargo plane operated by Air West of Georgia, which landed in Bangkok on Dec. 12.

All five crew were arrested, but it was not easy to trace the route the arms had taken. Alexander Zykov, a Kazakh dealer in illegal arms, is allegedly behind the transport. He hired five crew for an air freight company he owned named East Wing in Kiev, Ukraine, in July last year. Three days later, a friend of Zykov's established a ghost company named SP Trading in New Zealand.

SP Trading then leased the cargo plane from Air West, which is also effectively run by Zykov and had earlier leased it to Overseas Trading FZE, a company in the United Arab Emirates owned by Zykov's wife. Once SP Trading had leased the plane, it received an order from a Hong Kong-registered firm, Union Top Management, to transport "petroleum industry components" from the [North] Korean General Trading Corporation.

The plane took off from Kiev and flew via Azerbaijan and the UAE to North Korea. Once the freight had been loaded, it was scheduled to stop for refueling in Thailand and fly west to Ukraine by way of Sri Lanka and the UAE. From there, some reports say it was leapfrogged via Iran to Montenegro, but the tiny peaceful principality seems an unlikely final destination for the cargo.