"Earlier reports the incident occurred as a result of a collision between two tankers are incorrect."
Mr Milne's family and friends have voiced their sorrow at his death and paid tribute to him.
Sonny Te Ako Tahi said on Facebook he was saddened to hear the news, and Mr Milne was his neighbour.
Mr Milne's wife Janette told Fairfax her husband had been driving trucks for 41 years.
"He had lots and lots of friends ... he was very well-known," she said.
"He was a great family man, a warm, loving person who would do anything for anybody."
Terrence Karl Bach said on Facebook Mr Milne was "always there" where needed and was "gone but never forgotten."
"He will be flying high looking down on you all," Vicki Greening posted.
Police were assisting WorkSafe New Zealand in the investigation into Mr Milne's death, Mr Friend said.
"On behalf of New Zealand Police, I would like to pass on our sympathies to Mr Milne's family for their loss," he said.
The death has been reported to the Coroner.
The rural Waikato community has been left saddened following the death.
Emergency service, which was called to the scene about 1pm, found the man severely burned. He died at the scene.
Otorohanga District Council Mayor Max Baxter said the workplace death was a tragedy, and people in the community would be saddened by the news.
"It's tragic, it's horrific," he said. "I just really, really feel for the family concerned, the colleagues, the employers. It's horrible.
"It's a horrendous and very unfortunate workplace incident."
He added: "From my perspective, and from the community's perspective, it's just a very, very sad day for the family, and my sympathies and condolences go out to them."
Mr Baxter, who lives close to the Corboy's depot, said details of the incident were still unclear, but he was confident an investigation would be thoroughly carried out.
"I'm sure as time goes on, we'll find out more details as to what actually happened," he said.
"This will be investigated by WorkSafe and they'll come up with all the answers as to what's gone wrong, what practices need to change [if any].
"No business owner would ever wish this upon anybody in their workplace."
Corboy Earthmovers had been in business for a number of decades, Mr Baxter said, but was now under new ownership after the original founder - Craig "Cactus" Corboy - died in a digger accident about three years ago.
"But it's certainly been a local part of the district for many, many years now," he said.
The Waikato Westpac Rescue Helicopter was sent to Te Kawa with a medical crew on board about 1pm yesterday.
A 60-year-old man had sustained life threatening injuries, the chopper agency said.
"The man was being treated by St John [Ambulance] staff at the scene when the helicopter arrived with medical support."
No further information was provided, and a spokeswoman for the rescue helicopter referred questions to police.
There was no answer at Corboy Earthmovers this morning, and the company has yet to reply to emails.
Police referred all queries to WorkSafe New Zealand. The workplace regulator confirmed it was investigating, but said it had no update to release today.
Te Kawa Waitomo petrol station owner Paul Sandhu said everybody in the district who knew about the accident was devastated, and he hoped the man's family were being supported.
"It's really hard for the family."
Corboy owner Brent Pevreal came into the service station later in the afternoon, he said.
"Everybody I've seen was really upset ... The guy who owned the company was here earlier and he was really sad, too."
Mr Sandhu said he just heard one massive "bang" when the tanker exploded.
Another neighbour heard a similar explosion. About 20 minutes later, she saw the Corboy premises swarming with emergency-service personnel, and the Waikato Westpac Rescue Helicopter on site.
The workplace fatality was November's third. John Douglas Howe died last Wednesday when he was hit by a truck at a Mangere freight yard, and Mario Lelina was killed using machinery at a Southland gold mine on November 5.
Council of Trade Unions president Richard Wagstaff said the union was very concerned at the number of people being killed at work, "and today's death comes on top of far too many this year".
The country needed the situation to "improve dramatically", he said, although legislative changes had helped achieve some progress.
But provisional statistics suggested about two-thirds of this year's workplace deaths had happened in industries the Health and Safety Reform Bill did not categorise as dangerous, he said.
Northern Fire Communications shift manager Megan Ruru said the tanker exploded on site.
One of the trucks which had a tank on it was thought to have just returned from Hamilton.
The Herald was yesterday told the tank was being filled up, parked next to another tank, when the blast occurred.
WorkSafe New Zealand was notified yesterday afternoon, and is investigating. Police are also carrying out an investigation on behalf on the Coroner.
Nobody at Corboy was immediately available to comment yesterday afternoon and police said staff at the company were too distressed to speak.
According to Corboy's website, the business has been providing "high-quality services to the rural sector" for 35 years.
Corboy works on projects including bridges, underpasses, effluent pond construction and civil roading, excavator work and urban driveway entrances, according to the website.