The dogs have been taught to recognise a specific odour in sweat samples and the aim is to use them alongside required PCR testing for international passengers from early next year.

"We've done it in training and our next step will be to deploy in airports with incoming international passengers," Adelaide University researcher Susan Hazel said

"The benefit will be, once we can prove that it is working, that they could be used without the other testing, they could be used for initial screening."

International examples in the field also show the dogs could be effective in detecting the virus in pre-symptomatic cases.

While results need to be verified, Dr Hazel said dogs had indicated a positive case after an initial PCR test showed a negative.

"When they've gone back and retested the people they've been positive," she said.

"So it looked like they were pre-symptomatic, so the dogs may be able to pick up people before they can be picked up with the other tests."

The project is a collaboration between Adelaide University, Australian Border Force, Biosecurity, emergency services and international partners.

Dr Hazel is working with lead researcher Anne-Lise Chaber from the university's school of Animal and Veterinary Sciences.

She said the dogs were introduced to positive samples to imprint on in a method similar to the training for drug detection.

While the use of different chemicals and masking agents can complicate drug detection, there are different challenges for recognising the virus.

Allowing for different ages, genders and backgrounds has been an important part of the training process.

Based on overseas experience, Ms Hazel said the dogs don't tend to pick up on other viral infections.

"It seems to be something quite specific to COVID-19," she said.

International teams are trying to isolate the scent the dogs are recognising.

Australian Associated Press