Solid Energy is auctioning off equipment from the Pike River Mine more than four years after the disaster.
The sale includes the complete coal processing plant and more than $4 million worth of spare equipment.
An advertisement in Saturday papers described the equipment as built new in 2008 and being used for less than two years.
It said everything must be sold and the site cleared by the end of June.
Spokesperson for the families Bernie Monk said none of the equipment being sold had any value to the families, and was not anything they wanted to keep for a memorial site.
"We were given the opportunity to have anything we wanted," he said.
"But what they're selling is of no use to us and if the families themselves wanted something privately for themselves, they also had the opportunity to do that as well."
A spokesperson from Solid Energy said the company would have never sold off any Pike River equipment without consulting the families. He said there was no estimate of how much money the company would get from the sale.