The NSIA is an investigating authority in accordance with chapter 18 of the Norwegian Maritime Code. The objective of NSIA is to determine the course of events and causes of an accident, give an account of circumstances significant to the avoidance of accidents and improving the safety of life at sea, and to submit and publish a report with any recommendations upon the conclusion of the investigation.
It is not the task of NSIA to apportion civil or criminal blame and liability.

Link to NSIA, Shipping Department (Norwegian site)

Link to reports published by the NSIA, Shipping Department