Another friend said Mr Stainton had worked in the mine for more than seven years and knew "every aspect of the place".
He was regarded as a "great guy" as well as being a keen hunter and fisherman.
Mr Stainton's workmates also paid tribute to him in Facebook posts.
Police said Mr Stainton was found dead inside the wreckage after an underground mine rescue team carried out an overnight search.
Mining union E tū expressed its support and condolences, saying miners were much like a family and Mr Stainton's death was ''tragic" and ''untimely".
"The mining community is close-knit and in many respects like a family", union spokesperson Myles Lesson said.
"There will be grief and shock over what's happened, and we want to ensure people are well-supported", he said.
At a press conference yesterday, mine boss Bernie O'Leary said the loader Mr Stainton had been in rolled in a large open area called a stope, which was like an underground cave.
Mr Stainton had been backfilling waste rock into the void, a void created by mining out gold bearing rock, when the accident happened, with between 25 and 30 staff working on the shift at the time, he said.
"It was the first time in the company's 25-year history in New Zealand that a worker had been killed.
"Our thoughts are with the family and his workmates. We are supporting them as much as we can at this very difficult time, as we know the Waihi community will too."
Work at the mine had been suspended, he said.
OceanaGold senior community advisor Kit Wilson said it was far too early to speculate on the cause of the accident.
A Worksafe spokesperson said its inspectors assisted with the recovery of Mr Stainton's body, and an investigation team had began making its enquiries into the death.
The investigation would take some months to complete, and WorkSafe would not make any further comment at this time, the spokesperson said.
Hauraki Mayor John Tregidga said the mine had a good safety record.
"Training and the Worksafe practises in the mine were extremely high and this was a very unfortunate incident, and the whole community would be feeling for the family," he said.
Police Area Commander Inspector John Kelly thanked all those involved in the rescue operation and offered his sympathies to the deceased family and friends, as did Coromandel National MP Scott Simpson.
The tragedy happened a couple of weeks after the mining company lodged a draft resource consent application for a new underground mine to be located in the area between Correnso and the eastern boundary of the Martha mining licence.
OceanaGold requested that the application be considered on a non-notified basis.
Waihi esidents were reeling from the news of Mr Stainton's death, yesterday.
"It's a sad day for Waihi and I was really shocked when I heard. My thoughts go out to the worker's family, friends and work colleagues, " said a long-standing Waihi resident.
Another long-term resident, who wished to be known only as Kaye, said the death was "tragic".
