The Daily Freight driver was driving along the Christchurch Southern Motorway about 7.40pm on September 5 when the fire started inside the cab.
The Star understands the fire was caused by a mechanical fault.
WorkSafe New Zealand has been notified of the incident and is making initial inquiries to determine what the next steps will be, a spokeswoman said.
Daily Freight is owned by Mainfreight.
Said Mainfreight national manager transport New Zealand Carl George: “The driver will be okay and the truck is being looked at.”
He said the incident will be dealt with in the appropriate manner internally.
The driver was left with moderate injuries, including burns to both legs.
The fire closed off one lane of the motorway, near the Curletts Rd off-ramp.
