Australia has suspended the licence of the country's largest natural products manufacturer. It's the largest health-related recall in the country's history.

Australia's prime minister urged people to stay calm after 219 products ranging from cod liver oil products to ginkgo biloba were recalled because of substandard practices and adverse reactions.

Pan Pharmaceuticals calls itself the largest independent contract manufacturer worldwide. Pan represents 70 per cent of the Australian non-prescription market and exports to dozens of countries in Asia and Europe and United States.

The Therapeutic Goods Administration, the Austalian equivalent to Health Canada, suspended Pan Pharmaceuticals' licence on April 28 for six months after it discovered that the company substituted some of its ingredients, manipulated test results and released products that contained materials not tested for safety.

"On the evidence available, TGA had no alternative other than to do what it's done, and we will continue to throw the book at anybody who doesn't match up to the standards that have been set," Australia's prime minister John Howard told a Melbourne radio station.

The government started investigating Pan Pharmaceuticals when consumers first complained in January of hallucinations and other adverse reactions from the company's travel sickness tablet, Travacalm. Nineteen people were hospitalized.

The company also makes over-the-counter medicines such as codeine and antihistamines.

TGA warned that thousands more products may be recalled as it tries to track down products that Pan manufactured under licence for other companies.