The Australian Competition and Consumer Commission (ACCC) relaxed rules across the economy so banks, medical companies, supermarkets, energy suppliers and telecommunications firms could legally collude rather than compete.

"No, we do not want to keep that going," ACCC chair Rod Sims told a parliamentary committee on Wednesday.

"It would loosen the pressure that competition brings to our economy."

Mr Sims said all measures should be unwound by the end of September, although it would be a simple job to extend some on a case-by-case basis.

But he says there is a legislative issue that needs to be aired, as usually consumers have a right to a refund, but consumer guarantees did not apply during the pandemic.

The ACCC was not prepared for that, he said.

"There was real concern about how people would get groceries, including how to get more toilet rolls on the market," Mr Sims said.

There was also a push to get 24-hour access to supermarkets during outbreaks, and chains agreed between themselves to limit the number of toilet rolls people could buy.

Quizzed by Liberal committee member Jason Falinksi, Mr Sims said the ACCC was also looking very closely at plans from Coles and Woolworths to combine their power to buy stock, but it did not yet require any enforcement action.

The ACCC established a COVID-19 taskforce to respond to a surge in complaints sparked by restrictions, including a 500 per cent increase in grievances and reports about the travel sector.

Commissioner Sarah Court said businesses were being increasingly upfront about hotel and travel interruptions, and complaints were easing off but still higher than at the same time a year ago.

Australian Associated Press