An urgent investigation is underway after a man got trapped in a council recycling truck in Wellington.

Emergency services were called to Upton Terrace in Thorndon shortly after 10.30am today where the man was found unconscious.

He was pulled from the glass recycling truck and taken to Wellington Hospital in a critical condition.

Wellington City Council who operates the recycling company Envirowaste, says a full investigation will be carried out once they've determined whether it was caused by mechanical or human error.