More than 100 complaints of rapid antigen test (RAT) price gouging are being made to the consumer watchdog every day.
The Australian Competition and Consumer Commission said it continues to receive a high number of reports, and is investigating several for breaches of consumer law.
"The ACCC has received almost 3,900 reports from consumers about rapid antigen tests between 25 December 2021 and 26 January 2022, averaging about 121 reports per day," the commission said in a statement.
"Pharmacies have been the most-complained about sector, attracting 1,309 complaints, or almost 34 per cent of reports."
The ACCC said complaints about pharmacies outstripped petrol stations, convenience stores, tobacconists and supermarkets, where rapid tests have also been regularly sold.
However, it said, in recent days it had received a growing number of complaints about smaller stores that "would not usually sell such items".
ACCC chairman Rod Sims said the organisation had received over 130 reports about IGA stores, and 72 for BP branded petrol stations.
“So we're trying to send a message out to head offices, if you have stores as part of your network that are doing the wrong thing, get them to stop it otherwise you will be named and further your stores may find themselves in court for unconscionable conduct,” he said.
The ACCC said analysis of the reports made to it indicated that people were still paying about $24 per test, on average, although it notes more-reasonable prices may not have been reported to the watchdog.
Wholesale prices remain between $3.82 and $11.42 per test, according to the watchdog.
"While $20 retail prices remain lower than the more-extreme reports received by the ACCC, this is still an unusually high mark-up that, in our view, is very difficult to justify," ACCC chair Rod Sims said.
More than 50 rapid test suppliers, major retailers and pharmacy chains have now been asked to explain their costs, current pricing and stock availability.
The ACCC has warned test sellers must be able to substantiate any claims made to consumers about the reasons for higher prices.
It said several referrals had also been made to the Australian Federal Police as well as the medical regulator, the Therapeutic Goods Administration, following tip-offs about illegal re-selling of rapid antigen tests and alleged package-splitting and sale of tests not approved for home use in Australia.
"Community concerns about sales practices for rapid antigen tests remain very high, for good reason," Mr Sims said.
"We thank the consumers who have taken the time to pass on to us crucial information about what is happening in this market.
"These reports, and the public scrutiny, are helping to keep prices at lower levels than otherwise."