Based on local information, (not verified by myself) it would appear that an elderly person has received a telephone call purporting to represent NHS test and trace service.
The suspect told the person answering the phone, that they had been in contact with someone who had tested positive for COVID-19 and that they now needed to be tested within 72 hours.
The caller then said there was a charge of £50 for the test and took bank card details over the phone. (The long card number, expiry date, name on the card and CVC code giving the criminal all the detail they need to fraudulently use the card)
Any test under the NHS Test and Trace service is free.