Air Accident investigators are travelling to the West Coast today, to find out why a Robinson helicopter crashed.

The chopper came down near Karamea yesterday afternoon (Sunday Jan 2) , seriously injuring the pilot.

Stuff is reporting that the pilot is Tony Ibbotson, a well known local builder and butcher.

The crash scene is now a restricted site and two investigators from the Air Transport Accident Investigation Commission will gather evidence and secure wreckage and electronic records.

Chief Investigator of Accidents Harald Hendel said locals and holidaymakers who saw the helicopter in-flight or who witnessed the crash were asked to contact the commission.

He said investigators are particularly interested in receiving photos or videos.