ACCC gets more than 600 carbon complaints in 10 days

The federal government's $23-a-tonne impost on carbon emissions started on July 1.

The Australian Competition and Consumer Commission says of the more than 8000 general complaints it has received so far this month, 630 related to the carbon tax.

"Clearly the biggest group have been about energy retailers," ACCC deputy chairman Michael Schaper told ABC Radio on Thursday.

Other sectors included construction, landfill and refrigerant gases.

The commission says 20 cases are being investigated.

"If we come across businesses that are really setting out to dupe consumers ... then we will certainly go after them," Dr Schaper said.

Bakery chain Brumby's was still being investigated after management told franchisees they should use the carbon tax as cover for unrelated price increases.

Two solar companies, Polaris Solar and ACT Renewable Energy, earlier in July were found to have made misleading comments about the impact of the carbon tax on electricity prices.