Images captured through a borehole show evidence of further human remains inside the Pike River Mine.
The development comes after police confirmed at least two sets of human remains were found in November and another two - possibly three - a month later.
Taken in the goaf area of the mine, the latest pathologist-reviewed images show two sets of human remains.
Three men were believed to be working in this area when the West Coast mine exploded in 2010. Twenty-nine were killed and only two escaped alive.
Det Supt Peter Read said eight sets of human remains have now been located through the borehole drilling.
"While the discovery of these eight sets of remains is significant, I'm very aware that it still leaves many unanswered questions for the men’s loved ones and my thoughts are with all of the families today," Read said in a statement.
The borehole drilling programme began in 2019 and was originally meant to end late last year. However, police said in December additional borehole drilling had been approved - allowing the programme to continue into 2022.
"The drilling operation has provided police with valuable information to inform our investigation into the underground activity that led to the first explosion," Read said.
"On behalf of NZ Police, I would like to extend my sincere thanks to all those who worked on and supported the drilling operation, including Pike River Recovery Agency staff, and other drilling and mining experts."
He said a criminal investigation into the explosion was ongoing despite the borehole drilling operation now concluded.
Rowdy Durbridge, whose son Daniel Herk died in the mine, said the discovery was small but "knowing the boys didn’t die alone in there is a comfort to me".
"This has taken a long time but it's never too late for justice. I reckon my boy - all the boys I worked with - would be proud of the work done by families and the agency and the police to help put this to rights.
"We're thankful for that work."
Anna Osbourne's husband Milton was among the 29 killed in the 2010 explosion. She said the human remains discoveries were giving them answers about what happened on that fateful day.
"What is giving us some comfort is that now, as we get to the end of the project and the mine is sealed, we're getting real answers about what had happened there," she said in a statement. "Just to see that our men fell where they stood and didn't suffer for hours or more is so important."
Since the devastating explosion more than 11 years ago, families have repeatedly fought to honour the 29 who died in the explosion.
