The third phase of the Royal Commission into the Pike River disaster ends on Friday.
This phase is investigating what actually caused the explosions at the West Coast coal mine on 19 November 2010, which killed 29 men.
The commission has held six weeks of hearings since November on this part of the inquiry.
It now has a working theory for what caused the disaster - sparks from the restarting power system ignited a cloud of methane spread by an unexpected roof cave-in.
The commission hears its last evidence in this part on Friday morning and will reconvene in April for a short hearing on Government regulations.