Supermarkets and petrol stations are distancing themselves from a "too-good-to-be-true offer" luring Waitangi Day revellers.
The scheme was launched at the Treaty Grounds on Friday where cardboard cards were handed out.
They promised hundreds of dollars in retail credit to people who bought a $45 "credit exchange card".
Northland woman Bing Waitai, who was promoting the scheme on Facebook, said information had been distributed to more than 100 people at Waitangi. She referred calls to a credit exchange information line, which was answered by Paihia businesswoman Naomi Waterhouse.
Waterhouse told the Herald on Sunday the scheme was a different monetary system, based on the pre-Treaty Declaration of Independence, which avoided debt.
How much credit was loaded on people's cards would be based on their "worth as a human being".
"There is a $45 charge for the Eftpos card but once you join you have access to the credit exchange membership right away.
"Depending on your personal situation, you could get up to $50,000 in credits a year."
Waterhouse said New World and Caltex were among those signing up to the scheme - but both companies rejected this last night.
Foodstuffs spokeswoman Katherine Klouwens said: "If you see or hear about an offer that sounds too good to be true - it usually is a scam. We advise that if you see something in association with one of our brands that you are worried about, don't hesitate to contact one of our stores or Foodstuffs, so that we can verify the offer."
A Caltex spokesman said the company had not had any discussions with credit exchange.
One Kaikohe resident, who did not want to be named, said word of the scheme had spread quickly but she was suspicious. She had been told the only shop in the scheme was New World in the town.
New World owner and operator Eric Rush said he had heard rumours about it but was not involved. "No one has come to see me about it. It sounds a bit far-fetched to me."
Waterhouse, who runs a taxi firm, said she would accept the credits at her business. When contacted last night about the Foodstuff's and Caltex's comments, Waterhouse's husband Geoff said the companies weren't on board yet and his wife should not have spoken. He would not comment further.
Claire Matthews, director of academic programmes at Massey University and banking specialist, warned people against the scheme.
"There is no way you can expect to get x amount of anything just for being. It is going to cost you at some point. If that aspect is being sold as part of the scheme, it is a scam," she said.
"The website makes it look like a barter system, which would work for businesses up to a point but not for individuals."