Police are investigating fraud involving companies providing false letters of approval for COVID-19 rapid tests.
Therapeutic Goods Administration boss John Skerritt said the expanded use and availability of rapid antigen tests had brought with it "a lot of trouble with companies making false claims".
The TGA has so far approved 22 types of test kits, which Professor Skerritt said was more than the US.
Professor Skerritt told reporters in Canberra there were issues around companies forging documents.
"Police are looking into this - I won't comment further in any detail," he said.
Health Minister Greg Hunt said he had asked the Australian Competition and Consumer Commission to investigate claims by some companies that their stock of testing kits were being seized by the Commonwealth.
"They are lying - that is why I am reporting them to the ACCC," he said.
He said some suppliers had overcommitted and were unable to deliver.
And the global spike in demand for kits was disrupting supply to Australia.
However, one testing kit supplier told customers in an email, obtained by AAP: "The saliva tests were prioritised to the government's national stockpile and were pulled from under our nose - without prior notice - causing major delays."
"We are dealing with a high-volume backlog and limited resources, and we wanted to reassure you that we are taking action to deliver your orders as soon as possible."
