A coroner's ruled that an inquiry won't be opened into a Wanaka helicopter crash which claimed three lives

It comes after multiple investigations established the circumstances of the crash, and identified safety recommendations.

Pilot Nicholas Wallis and DOC workers Scott Theobald and Paul Hondelink were killed when their helicopter suffered a failure shortly after takeoff from Wanaka Aerodrome.

The Transport Accident Investigation Commission found the left-rear door likely opened unexpectedly due to wear in the latch mechanism.

It says the under reporting of doors opening in-flight was a factor.

Coroner Amelia Steel confirmed no inquiry would be opened, citing the thoroughness of existing investigations.