The UK government has admitted sending about 50,000 coronavirus tests to the US last week for processing after “operational issues” in UK labs.
The health ministry said that sending swabs abroad was part of the contingency to deal with “teething problems.”
The samples were flown to the United States on charter flights from Stansted Airport, the Sunday Telegraph said.
The results will be validated in the UK and sent to patients as soon as possible.
Results will be validated in the UK and sent to patients as soon as possible.
The revelation comes as the government failed to hit the 100,000 daily tests target set by Health Secretary Matt Hancock for the seventh day in a row.
There were 96,878 tests delivered in the 24 hours up to 09:00 BST on Friday, down from 97,029 the day before.
UK Prime Minister Boris Johnson has said his “ambition” was to hit 200,000 tests “by the end of this month – and then go even higher”.
BBC health reporter Rachel Schraer said the UK did not start with the resources to perform mass tests, unlike some other countries.
But it also took several weeks to move from the first eight public health laboratories to a larger network of private and university laboratories.
Unlike the UK, countries like Germany and South Korea quickly stockpiled kits and made the test available to more laboratories.