The New Zealand Transport Agency is encouraging couriers to speak up if they have concerns about excessive working hours.
A courier, Nathan Dodkin, was killed in a collision with a truck in Taranaki on Thursday.
The National Distribution Union says owner-operators are being forced into unfair contracts which lead to dangerously long hours on the road.
The Transport Agency's national manager for commercial operations, John Doesburg, says if those allegations are true, the situation is unacceptable.
He says the agency and police would want to receive information about any instances of drivers forced to work excessive hours.
Mr Doesburg says it is not yet known what caused the accident in Taranaki but it may indicate a need to look again at the regulations relating to couriers.