The world-first research from Melbourne's Doherty Institute found unique garlic varieties were able to reduce the infectiousness of the viruses by up to 99 per cent.

"We could barely detect any remaining virus genome, indicating nearly complete virucidal activity," the institute's Julie McAuley said.

The research released on Wednesday involved 18 months of in-vitro testing of garlic ingredients against the SARS-CoV-2 and influenza type A viruses.

The study was commissioned by Australian Garlic Producers, which is commercialising the most effective garlic varieties and their extracted ingredient.

The novel garlic extraction process is subject to a recently lodged international patent.

"Our extensive research over many years ... has shown that garlic varieties not only vary in their agronomic and physiological properties, but also in their biochemical properties," the company's chief executive Nick Diamantopoulos said.

"This type of detailed analysis is the key reason that has led to the identification of unique and specific garlic varieties with superior properties."

The Doherty Institute's business development director Martin Elhay welcomed the latest findings, saying the organisation was committed to the global effort to combat the spread of COVID-19.

Australian Associated Press