Mine safety consultant Dave Feickert has criticised Solid Energy's safety practices, saying the mining company is complacent and, at times, arrogant.
A worker at the company's Spring Creek underground coalmine near Greymouth was seriously injured by falling coal on Wednesday.
Mr Feickert says he used to think Solid Energy had good safety systems, but what he has seen in the past five years worries him.
"I've come to the conclusion," he says, "that they are a company that must raise their game. They claim to be best-practice, they claim to be introducing the Queensland model which is the world's best - well, not all of it, because they don't want to have check inspectors.
"They've made these claims and I'm afraid they have just not proven it."
Solid Energy chief executive Don Elder says Mr Feickert's comments are ill-informed opinions with no factual basis.
Mr Elder says health and safety is an area that will always need improving on, but "we are working extremely hard, with a huge amount of progress".
He says the number of risky incidents at Solid Energy mines has decreased significantly and continuously in recent years.
The injured miner is in a stable condition in Christchurch Hospital.