A truck explodes on a highway in Yueyang City, central China’s Hunan Province on March 19, 2016. [Photo: CFP]

An investigation has shown that the truck owner involved in a deadly explosion on a highway in China was not licensed for hauling dangerous goods.

The truck, which was suspected to be loaded with flammable and combustible materials, exploded on Saturday night on a section of the highway linking Beijing, Hong Kong and Macau.

Five people were killed and twenty others injured.

The owner, surname Zhao, is from Gansu province in the country's northwest.

A witness described the scene when the truck exploded. "There was a huge blast. I couldn't see anything when it happened. There were many vehicles lining up and the truck exploded in the middle of the line, in the carriageway. At first, there was a big fireball. Then I saw the vehicles were blasted away."

According to China Central Television, two cars and two trucks burned after the explosion, and several other vehicles were damaged.

Along with conducting a thorough investigation of the incident on the highway, police are also being forced to deal with rumours related to the incident.

Authorities have had to dispel inaccurate claims made online -- including a post that claims 78 people died and dozens of others were injured in the blast.

Local police in Jiahe county of Hunan province even re-posted some inaccurate information on their official Weibo account, but the message has since been deleted.