Dawn raids at Sydney trucking company

A Sydney trucking company whose vehicle was involved in a fiery smash that closed the M1 Pacific Motorway north of the city for nearly a day has been raided by authorities.

A joint operation involving police and Roads and Maritime Services inspectors was carried out in the early hours of Friday at a Blacktown business, with the company's trucks and trailers also slapped with a state-wide stop-and-search order.

Tuesday's crash between a B-Double and a mobile crane left cars banked up for 20km after the vehicles collided and burst into flames.