A "humble and hard-working" pig hunter from Papakura went to work and waited six hours on Monday before telling his wife he'd won $28.7 million in New Zealand's biggest single Lotto win.

And both of them are going back to work today.

Speaking exclusively to the Herald, the self-employed man said yesterday he kept quiet because he didn't want to distract his wife from her job.

"I picked her up after her work and asked her to shake my hand to meet New Zealand's latest millionaire."

Asked what was going through his mind during the day while he waited to tell her, he said: "Giving her the shock of her life."

That shock sent her into tears.

"We have been down to our last dollar a couple of times this year, so winning this much money is amazing."

He said he had no problem holding himself together in the hours before he broke the news to her.

"Oh that's easy," he said. "I'm a patient person ... I am a calm person."

He said he initially tossed his Lotto ticket aside after he saw the winning numbers on television on Saturday night.

"I had a quick flash through it and I go, 'Oh I didn't win' and just threw it on the floor. When I went to bed, I picked it up and put it on my desk drawer and left it there all day Sunday.

"After I watched the news and they said that it hadn't been cashed in yet, I thought, 'I've got a chance'."

It was not until about 9am on Monday until he found out he had won, after his daughter - who knew the winning ticket had been bought in Papakura - urged him to check his numbers online.

"We were just so overwhelmed with it all and she was just crying and couldn't believe it and going, 'No this is not true.' We checked the ticket quite a few times."

The man - who did not want to disclose either his occupation or that of his wife - said his hands were shaking so much he couldn't write his name on the back of the ticket but he managed to take a photo of it.

Because he doesn't like flying, he and some family members drove to Wellington to claim the prize yesterday.

He said the drive gave him "time to think".

His wife stayed in Auckland - "I sent her back to work."

The man had his lucky ticket in his wallet in the chest pocket of his camouflage hunting shirt when he arrived at the NZ Lotteries office to claim his prize.

He said he bought the $12 Power Dip ticket on an "impulse" after he stopped at Mobil on the Run in Papakura and the woman in front of him at the counter bought a ticket.

"Normally I go to a different shop, but that day I was watching this person and it made me want to buy the next one after her ... [I was] just watching her, and I go, 'Mmmm yes, what if?"'

The man said he bought Lotto tickets only occasionally - "it's just when I feel like it, when I feel lucky".

He had won "lots of $20s before" but had never had a major Lotto prize.

Sleep hadn't come easily since the win. "[I've had] a little bit ... one eye open maybe."

Asked how the win could change his life, he said: "I'm going through the stage of still thinking about it all, still trying to get it to sink in ... I don't know. I like the way my life is at the moment, so I hope I can still keep it that way, kind of. Probably impossible, but I'll try."

He had a large but close extended family who would be meeting this weekend to discuss how the money might be used.

He had a "couple of little" debts which the win would pay off.

He definitely planned to donate to charity but would do some research to find the right cause.

Appearing on reality television may not be out of the question in any charitable donation, he said.

"I like those programmes Undercover Millionaire, Undercover Boss," he said referring to Secret Millionaire, a show in which millionaires go incognito into poor communities to give away money.

The keen diver and fisherman said he hadn't yet made plans to buy anything, answering a question about what he might buy, with two simple words - "family discussion".

There had also been no thoughts of giving up his business - "I'm going back to work tomorrow".

Asked if he thought there might be a time that might change, he said again: "Family discussion."

The man said he had a "few" children aged from teenagers up but would not reveal any more details.

His stunned son, who also travelled to Wellington yesterday, said he was forced to listen to his father's "old style" music on the journey.

He said he learned of the win when his Dad beckoned him over.

"I came in and I was like, 'What?' and he's like, 'I won. I won the Lotto - $28 million.'

"I was like, 'Not even - you're lying' and all this, and I saw my sister crying and then she was telling me, 'It's true, it's true'."

NZ Lotteries spokeswoman Karen Jones said the man didn't want the Lotteries Commission to shout him lunch as a celebration.

"All he wanted was a hot chocolate and he was on his way."

The win was New Zealand's single biggest because a $36 million Big Wednesday prize won in June last year in Masterton went to a family syndicate of four people.

The next biggest Powerball win was $22.4 million, which went to a Manukau player in October last year.