The vehicle, which can transport and erect a missile for a launch, drew attention as it carried what is believed to be an intercontinental ballistic missile with a presumed range of up to 6,000 kilometers that is capable of reaching Alaska.
The 16-wheel erector-launcher is apparently based on a design from the 9th Academy of the China Aerospace Science and Industry Corporation, also known as the WoSang truck factory, said Ted Parsons of IHS Jane's Defense Weekly.
The Chinese and North Korean vehicles "have the same windscreen design; the same four windscreen wiper configuration; the same door and handle design; a very similar grill area; almost the same front bumper lighting configuration; and the same design for the cabin steps," Parsons said in an emailed comment to Yonhap News Agency.
Parsons said the Chinese company's involvement in North Korea's missile program would require approval from the highest levels of the Chinese government and the People's Liberation Army.
China is the North's key ally, economic benefactor and diplomatic supporter.
A South Korean official who handles North Korean affairs said it is fair to say that "all goods have been imported from China." The official spoke on condition of anonymity, citing policy.
"If confirmed, China's involvement in providing this erector-launcher to North Korea would put it in breach of U.N. Security Council Resolution 1874," said James Hardy, Asia Pacific editor of IHS Jane's Defense Weekly.
The resolution, adopted after North Korea's second nuclear test in 2009, prohibits supplying North Korea with any arms or related material, or providing financial transactions, technical training, services, or assistance related to such arms, according to Hardy.
He said China's possible support for North Korea's strategic weapons program could fatally undermine the six-party talks aimed at ending Pyongyang's nuclear programs.
North Korea quit the disarmament talks in April 2009 in protest of international condemnation over its failed long-range rocket launch earlier that month. The North conducted a second nuclear test a month later.
On Friday, North Korea's long-range rocket exploded soon after lift-off, with the pieces falling into the sea off South Korea's west coast.