An Auckland passenger train derailed earlier this year due to the failure to interpret signals, an internal investigation has found.
The train, which was empty at the time, was operated by Transdev Auckland and derailed on Sunday, March 2.
A copy of the recently completed report has been sent to the New Zealand Transport Agency and the Transport Accident Investigation Commission - who are working on an independent investigation into the incident.
Transdev managing director Terry Scott said the report's findings had also been released internally so lessons learned could be shared and future incidents prevented.
"Safety is Transdev's highest priority. It is important that the investigation process is transparent and that we learn from any incident.