Police are assisting Fire and Emergency New Zealand after a three-vehicle crash caused a diesel spill on State Highway 1 in Orewa.

The northbound lanes were blocked following reports of the crash at about 12.18pm.

One person has received injuries.

Both northbound lanes are closed from the Grand Drive off-ramp and traffic is being diverted.

Motorists are advised to expect delays and seek an alternative route or delay travel if possible.

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