Police are appealing for information from anyone who witnessed a motorcycle crash north of Auckland earlier this month.

The motorcyclist crashed somewhere between Helensville and Warkworth between 11.30am and 1.30pm on Saturday 11 November.

Sergeant Blair Atkinson of the Serious Crash Unit said it was possible the rider might have been assisted by a member of the public before getting back on his bike.

Atkinson wanted anyone who might have witnessed the incident or assisted the rider to contact him on (09) 481 0780.