A trial to see whether dogs can detect coronavirus is going "very well", according to the charity behind it.
Six dogs are being trained by Medical Detection Dogs in Milton Keynes.
Claire Guest, the charity's co-founder and chief executive, said the dogs were already showing signs that they would be able to sniff out the virus.
She has previously trained dogs to spot the scent of malaria, cancer and Parkinson's disease.
"The study is moving forwards very well and the signs are all really positive," said Dr Guest.
"At the moment, we are cutting up tiny strands of a tennis ball, and then touching the strands with a piece of paper and hiding the paper, and they are able to find it. They are incredibly skilled."
Norman, Digby, Storm, Star, Jasper and Asher will be trained to smell the virus on sterilised socks, stockings and face masks worn by NHS staff in London.
The team expects the 3,200 samples to start coming back next week. Scientists will work out whether they contain the virus and the dogs will be tasked with spotting the positive samples from the negative ones and alerting the trainers.
Dr Guest said her rescue dog Asher has been doing "exceptionally" well in training. The cocker spaniel was rehomed seven times because of his high drive before he found a home with her.
"He had already learned how to spot malaria and Parkinson's so we knew he would be well suited to this. He has been finding the training odour without any errors," she said.
"He is really leading the way and Storm is also doing incredibly well. He is very driven and really enjoying the work."
After eight weeks' initial training, the successful dogs will move on to a second phase to test them in live situations.
It is hoped the scheme will be expanded and dogs will be able to screen up to 250 people per hour, potentially at airports. They could also be used at testing centres.
The trial, backed by £500,000 of government funding, involves scientists from the London School of Hygiene & Tropical Medicine and Durham University.
Dr Guest started training dogs to detect cancer in 2002 and set up the charity in 2008.
A year later, her fox-red Labrador Daisy, trained to detect bladder and prostate cancer, started pawing at her chest.
Doctors discovered she had a breast cancer tumour so deep it would have been very hard to detect had she not been alerted.
"I know from my own experience how clever these dogs are. They are primed and ready for the task and we are very optimistic we can help in the fight against coronavirus."