Australia's competition watchdog says it has already come across businesses using the imminent introduction of the carbon tax to gouge consumers.
Australian Competition and Consumer Commission chairman Rod Sims told ABC Radio there have been claims electricity prices would increase by extremely large amounts - even hundreds of per cent - because of the carbon tax.
He said the aim was to encourage people to buy alternative energy based on wrong information.
Some businesses such as petrol stations were telling customers fuel prices had gone up because of the carbon tax - even though it doesn't start until July 1.
That stunt had also been tried by taxi drivers, cafe proprietors and even a brickworks, all apparently to explain away normal price rises.
In other cases some construction firms had said "buy now and beat the carbon price".
"It's very hard to see how if you buy now that will in fact be the case," Mr Sims said.
"We have probably only had about 250 complaints at our information centre and probably only about 100 of those relate to misleading and deceptive conduct.
"So it's low-level now but it is something we are watching very carefully."
Mr Sims said the ACCC could issue warning letters or require businesses to make court-enforceable undertakings not to do it again.
The watchdog can also exercise a new power requiring businesses to substantiate their claims.
Ultimately, it can prosecute with penalties of up to $1.1 million for each offence.