Three investigations are under way into how a recycling truck driver became trapped in the vehicle's hydraulics, leaving him seriously injured.
The driver remains in critical condition in Wellington Hospital after the incident on a Thorndon street in the central city yesterday
Investigations into the accident are being conducted by WorkSafe, the police, the Wellington City Council and the waste removal firm involved, EnviroWaste.
EnviroWaste managing director, Gary Saunders, said he did not believe a mechanical fault was to blame.
He hoped to speak to investigators today to find out what they have learned, but said it could be two or three days before EnviroWaste gets its own look at the vehicle, which has been impounded.
The driver was working alone, but Mr Saunders said the truck was designed to be operated by one person, and had safety mechanisms designed to protect workers.
Mr Saunders said that for now, the company was focused on supporting the man's family.