Police are seeking public assistance after a large amount of copper pipe and valuable fittings were stolen from a storage facility in North Rocks overnight.
Officers from The Hills command were called to the plumbing supply business in Loyalty Road about 4.20am today (Tuesday).
A short time later, bystanders discovered a nearby trailer — heavily laden with copper pipe — had been involved in an incident.
Witnesses told police a dual axel trailer was being towed by a gold Holden sedan when it appeared to jack knife in the street.
This resulted in six metre lengths of copper pipe hitting the road and causing the trailer to lift off the ground.
A second vehicle and trailer attended and two men unhitched the trailer from the Holden which drove away leaving the trailer in Loyalty Road.
The second man returned to his vehicle, believed to be a white Holden Rodeo or Mazda Bravo.
This vehicle was also towing a double axled trailer with a cage on it.
The vehicle and trailer were last seen on North Rocks Road travelling towards Parramatta.
Investigators believe at least 22, eight-inch copper pipes in six metre lengths were taken, along with a large quantity of brass fittings.
Anyone with information, call Crime Stoppers on 1800 333 000.