Video report by ITV News Royal Editor Chris Ship
The dogs and their handlers from the charity Medical Detection Dogs spent the morning training at London's Paddington Station before showing the Duchess of Cornwall and the health secretary what they can do.
The animals can sniff out the virus in humans in less than a second - even those who have it asymptomatically and are not showing any signs of coronavirus.
Health Secretary, Matt Hancock said on Tuesday: "You can immediately think of the number of uses that we could put this to - and find people who don’t know they have Covid."
Camilla, who is Patron of the dogs' charity, told us she was hopefully that the government would take notice of the dogs' progress.
"How could you not be impressed by them," she said after watching the demonstration with the Secretary of State.
The dogs have learned how to detect the virus in laboratory conditions but this was the first time they've been taken to a location where they might soon be detecting Covid-19 in a train-load, or a plane-load, of passengers.
Covid - like many diseases - has an ordour.
The Medical Detection Dogs also trains dogs to detect cancer, Parkinson's disease and diabetes.
This scientific trial, with the London School of Hygiene and Tropical Medicine is advancing well but they only have half the number of positive samples they need.
Professor James Logan from LSHTM urged anyone who has tested positive for coronavirus to contact them to get a sample pack which the dogs will then sniff.
The pack contains a mask, a t-shirt and socks which anyone with a recent positive test is asked to wear for a few hours before sending them back.
The trial is also working with airports to see how the dogs might be used there to open up travel once again.
Claire Guest, the co-founder of Medical Detection Dogs, said today the animals could be a "gamechanger" for passengers travelling under Covid conditions and today was a "fantastic opportunity to demonstrate to the Secretary of State how quickly these dogs can work".
Anyone with a positive coronavirus test and wants to help the trial can contact the team at www.virusdogs.com