The Therapeutic Goods Administration (TGA) has written to Clive Palmer and a regional radio network to express concern over ads that spread false information about the risks of COVID-19 vaccines.
The ads, endorsed by the former mining magnate, have been aired on Grant Broadcasters Radio stations and question links between COVID-19 vaccinations and deaths.
The TGA said misinformation posed an unacceptable threat to the health of Australians.
"Such misinformation, in the course of the COVID-19 pandemic, poses an unacceptable threat to the health of Australians," the TGA said in a statement.
"The head of the TGA, Adjunct Professor John Skerritt, has written to both Mr Palmer and the CEO of the Grant Broadcasters Radio network to remind them of this responsibility."
The national medical regulator said it has only found one case where a person with vaccine-related thrombosis with thrombocytopenia syndrome (TTS) or any other related condition died.
"Vaccination is the most effective way to protect against infectious diseases such as COVID-19," it said.
"When you get vaccinated, you are protecting yourself and helping to protect the wider community."
In a statement, Grant Broadcasters said the ads were no longer running on the network.
"Our radio stations strongly support their local communities and that includes fully supporting initiatives that keep our community safe, like the federal and state government COVID-19 vaccination programs," it said.
"The Therapeutic Goods Administration (TGA) has acknowledged the concerns we raised regarding this messaging and we are grateful to the TGA for stepping up to provide a clear statement of the federal government's position on this type of political advertising."
The Australian Communication Media Authority said it did not oversee the regulation of advertising, and referred the matter to Ad Standards.
The ABC understands that Ad Standards has received multiple complaints.
