On Wednesday, the search was narrowed to 379 households in the south of England, and that person has now been traced.
This variant of concern - known as P.1 - was detected in Brazil and in travellers from Brazil to Japan, and was associated with a surge of cases in Manaus late a year ago.
"The best evidence is that this person in question stayed at home and there's no sign that there's been any onward transmission", he said, adding the person was located in Croydon in south London and testing in the area had been increased as a precaution.
Scientists have identified 16 cases of a new coronavirus variant in the UK, Public Health England (PHE) has announced. "COVID-19 is still with us and we do not want these variants to get a foothold in our region and reverse all of your hard work", Lock said.
During Friday's Downing Street briefing, health secretary Matt Hancock confirmed the mystery person had been tracked down.
Biden limits eligibility for stimulus payments under pressure from moderate Senate Democrats
Senators are gearing up to vote on the package, which is expected to hit the Senate floor as early as this week. Centrist Senate Democrats had initially pushed for even more aggressive restrictions on the stimulus payments.
A study this week suggested that between 25% and 61% of people in Manaus who previously had Covid were susceptible to reinfection with the P1 variant.
New vaccines, particularly "tweaks" of existing products, are already in the development pipeline, but their necessity raises the prospect of long-term repeat-vaccination programs being needed for some time to come.
Kuala Lumpur: Malaysia has detected its first two COVID-19 cases of Nigerian SARS-CoV-2, also known as the B.1.525 variant, in two infected foreign nationals who had flown in from the United Arab Emirates (UAE), said Health director-general Tan Sri Dr Noor Hisham Abdullah.
He said coronavirus cases, hospital admissions and deaths are all continuing to fall.
And another 376,244 people received their first dose of the Covid vaccine yesterday.