Dylan O'Brien's injuries have forced production on Maze Runner: The Death Cure to be shutdown indefinitely.
Last month the 24-year-old star of the movie was dragged under a vehicle while shooting scenes for the next instalment of the franchise.
It has now been revealed he needs "more time" to get back to full health, with his publicist Jennifer Allen saying in a statement: "His injuries are very serious, and he needs more time to recover."
Dylan's accident took place in Vancouver, Canada, on March 17 and his director Wes Ball initially reassured fans that the actor and his good friend would be "fine" to return to work after a few weeks of rest.
In a handwritten note shared on Twitter, he wrote: "It's scary seeing your friend get hurt, but fortunately, Dylan is going to be just fine. After a few weeks of rest and recovery he'll be back up and running to finish our adventure together."