A tour guide has been called a hero for dragging more than 20 people off Whakaari/White Island in suffocating conditions.

White Island Tours manager Paul Kingi had just left the island with his tour group when the volcano erupted shortly after 2pm on Monday.

Paul recounted the experience to friend and former employer Rick Pollock, a former charter boat operator.

Rick spoke to RNZ about Paul's incredible actions in the most challenging and tragic of conditions.

"He actually wasn't the skipper of the boat [at the time] and that's really quite fortuitous because had he been the skipper he wouldn't have been able to co-ordinate things as well as he did. And his input was absolutely vital at that time," says Rick.

"Had he been the skipper he would have had that responsibility too and he couldn't have spread himself too thin. But Paul, being a free agent, was able to get back on the island and pretty much perform all the heroics."

Paul got into an inflatable dinghy and made his way back to the erupting island.

"He just charged back into that crater and was just pulling people off left right and centre - I think he pulled in excess of 20 people out."

Just as he was giving up hope of finding any more survivors, Rick says Paul saw a figure through the ash.

"He said that the atmosphere was acidic, acrid and just horrible and he was really starting to get concerned for himself when he saw him.

"That was the last person he rescued. And that man, he said, had a full inch of ash all over him."

Rick also got the terrible news yesterday that one of his and Paul's former workmates and good friends, Hayden Marshall-Inman, was among the dead.

Hayden Marshall-Inman. Photo: Supplied/ Facebook/ Stephen Parker.

"I'm devastated. Absolutely, utterly devastated. Hayden was one of my relief crewmen and was just about my second son - I knew that boy very wel."

Paul was also his mentor and the two were very close.

Rick says despite having a thick skin, the ordeal was going to be very hard on Paul, particularly given what he witnessed on Monday.

"Paul's just a legend. I've known him for a long time and I've never known a more resourceful person, I've never met a person who's able to grasp a situation so quickly and to act so properly every single time.

"I've been on an uninhabited island with him shipwrecked for five days and he did all the same things there.

"Nothing that he did on Monday surprised me but I had to mention [it] because they're talking about the helicopter pilots being heroes - and I have no doubt that they were and are - but Paul flies under the radar so often and he's just such an incredible guy in every instance and he really showed it yesterday. He really put his life on the line."