A company in Co Antrim producing coronavirus home-testing kits has distanced itself from a private London clinic that has been criticised for selling the item at three times the normal price.
Randox Health, which has its headquarters in Crumlin, has issued a statement saying it does not have a "direct customer relationship" with Private Harley Street Clinic.
The company, which is registered to a virtual office in central London, has claimed to have taken thousands of orders for the testing kit by selling it as part of a "service" for £375.
Randox Health sells the kits for just £120.
Following reports that the clinic may have profited by as much as £1.7m, it insisted that its £375 service was "not just a test" and included a telephone consultation with its director, Dr Mark Ali, if the test came back positive for Covid-19.
"We offer a clinical service which includes all the logistics and clinical support throughout the process and beyond for coronavirus testing," the firm said.
"The test is a panel test which will differentiate between the lethal Covid-19 virus and nine other non lethal viruses with the same symptoms."
The clinic is now offering refunds to any customers who have not yet received their testing kits, after the suppliers ran out of stock and stopped taking new orders until March 30.
"These supply delays have already caused significant anxiety for our clients," the clinic said.
"As a consequence, the only course of action we can take is to refund everyone whose kits have not yet been dispatched."
The clinic was accused of "profiteering behaviour" by shadow health secretary Jon Ashworth, who called on the Government to "stamp out this exploitative behaviour".
But Dr Ali rejected the criticism, telling The New York Times that his clinic "met a national need when the Government was doing very little". He had previously claimed to have sold more than 6,600 tests in a week.
In a statement, Randox said it had not supplied the Private Harley Street Clinic with their kits and was selling the kit at a "competitive price".
"These are unprecedented times and an unparalleled public health threat. As a private company with over 40 years investment in and commitment to the diagnostics industry, Randox quickly developed a Covid-19 test and were able to provide that test, with a home sample collection capability, at a very competitive price," they said.
"That price is a matter of public record.
"Randox do not have a direct customer relationship with this clinic, we have not supplied them and have no control over what they charge if they have accessed our kits. Likewise, we also have no control over what their customers are prepared to pay."
Public Health England is advising against using home testing kits, insisting the results are not necessarily "reliable".