There is still no indication as to how a man became trapped in a recycling truck he was operating in Wellington.

The man was working for recycling company Envirowaste in Thorndon yesterday when he became trapped.

He was rushed to hospital in a critical condition.

Managing Director of Envirowaste Gary Saunders says they still have no idea how the incident occurred.

He says they're trying to get hold of their vehicle and witnesses before they can say what might have happened.

"We're trying to get access to the various people on the scene, until we can achieve both those outcomes it's a bit of speculation on our part."

"Until we get access to the people that were on the scene, find out what they saw, what transpired, we're only just second-guessing."