Detective superintendent Darryl Sweeney Photo: RNZ / Maja Burry
New images showing considerable damage to the main fan at Pike River will help aid the criminal investigation into the first explosion in November 2010, police say.
The images have been obtained from the drilling of the latest boreholes.
Police announced last September they were reopening the borehole drilling operation as part of an investigation to determine what caused the explosion that killed 29 men.
Work began on the first two of 10 additional boreholes in late January and drilling was completed just over a week ago.
Detective superintendent Darryl Sweeney said initial analysis of images at the second hole, located by the main fan, showed considerable damage.
"We can see the roadway connecting the fan area to the drift has completely collapsed.
"The fan shaft and some of the housing for the fan blades can be seen, as well as the fan motor."
The last concrete block is removed from the 30m seal at Pike River Mine in 2021. Photo: Pike River Recovery Agency / Supplied
Sweeney said the video would be studied further, but initial analysis provided useful information which would further inform the police's ongoing criminal investigation into the first explosion at the mine.
Drill rigs have now been moved to the next two drilling sites - at the end of the drift, in an area known as Spaghetti Junction, and at an intersection near the goaf intake road.
Weather dependent, the boreholes will take between five and 10 days to drill, with imaging expected to take place within the fortnight.
It is expected all boreholes will have been drilled by the end of May, depending on weather.
Images of the men who died in the mine when it collapsed in 2010. Photo: RNZ / Nate McKinnon