The prize, $500,000 from Lotto first division and $5 million from Powerball, was struck in Saturday night's draw.
It is the sixth time this year the top Powerball prize has been won.
The winning ticket was bought at the Kihikihi Bookshop, but owner Young Yeo and his wife, Susie, didn't know their shop had sold its biggest winning ticket until the Herald contacted them yesterday.
Mr Yeo said it would be a good thing for the town, which Census 2006 showed had a population of 1959 - 18 more than in 2001.
He said about 80 per cent of Lotto customers at the store on State Highway 3 were locals, but "a lot of truckies" also bought tickets there.
"We really hope this has gone to a local person. It has been quite difficult times for people, so it would be nice to see our community happy again."
Lotteries Commission spokeswoman Karen Jones said yesterday that the winner had not come forward.
And despite locals believing otherwise, she thought it unlikely the winner would present their ticket in Kihikihi.
"For a prize of this size ... it's not something they will want to check at their local shop knowing that there would be a bit of a fuss made of them."
Ms Jones said most winners went to Wellington to collect their prizes, as they received their money more quickly than by claiming it through a local outlet.
Saturday night's jackpot comes two weeks after a $6.5 million Powerball prize was won by an Auckland couple, who flew to Wellington and caught a bus from the airport to collect their windfall.