A private healthcare clinic in London has defended its decision to charge £375 ($434) for a coronavirus test.
The Private Harley Street Clinic said the price reflected "the costs of these logistic and clinical services that we provide" and added that it was offering free tests for NHS staff.
It followed newspaper reports that the clinic had sold several thousand at full price.
According to its website, the test is no longer available.
In a statement released on Monday, the clinic said it was "pausing" the service now that the UK government has committed to carrying out more tests nationwide, with an aim to carry out 25,000 tests a day within four weeks.
Chief executive Dr Mark Ali did not respond to the BBC's request for comment.
It is believed the test offered was made by a firm called Randox Health, which was selling them online for £120 each, although according to its website it is currently out of stock.
Randox Health, which is based in County Antrim, Northern Ireland, was also contacted by the BBC.
Public Health England currently does not advise buying home tests. It says there is not yet enough information about them.
"It is not known whether either a positive or negative result is reliable", reads a statement on its website.
A spokesman for the General Medical Council said: "We expect doctors to be clear about the safety and accuracy of Covid-19 tests, and not to offer or recommend tests that are unproven, clinically unverified and/or otherwise unreliable."
Prof Martin Marshall, chair of the Royal College of GPs, said the needs of NHS staff and patients should be "put over making profit from the situation".
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The Private Harley Street Clinic said it had never advertised its service.
Google told the BBC that while it did not have a specific rule about ads for coronavirus tests, it had placed the pandemic under its "sensitive events policy", which means ads are banned which "may capitalise on tragic events such as a natural disaster, conflict or death".
Facebook said that test kit ads were banned.
Australian firm Rapidward said that five days ago it began supplying Covid-19 blood tests direct from China to Switzerland, Italy and Iran at a cost of $12 each, including shipping.
The test, which detects antibodies, claims to be around 95% accurate. It has not yet been approved by the Federal Drugs Agency (FDA) in the US but it is registered with the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK.
The firm said it would not sell to individuals.
"The kits are simple enough to be used by individuals, but we want to supply the medical industry and healthcare sector," said founder Milton Zhou.
Mr Zhou added that he believed it was "outrageous" to charge more than the cost price.
Academics at Leicester University are developing a mask-based test that could cost just £2 per unit, it said.
The mask collects a sample of what the wearer is breathing out - which then requires laboratory analysis.