British health officials are on the hunt for one of six people confirmed to have contracted a COVID-19 "variant of concern" from Brazil.
Six cases of the P.1 variant fist observed in the Amazonian city of Manaus have been detected in the UK — three in Scotland and three in England.
Authorities are looking for one of the English cases to come forward as they remain unidentified.
Public Health England said in a statement that the individual did not complete their test registration card "so follow-up details are not available." They are appealing to people who undertook the test on February 12 and 13 and who have either not received their result or have an uncompleted test registration card to reach out as soon as possible.
The Manaus variant has been deemed "of concern" by British health officials because it shares some important mutations with the South African variant which was found to be up to 70 per cent more transmissible.
"It is possible that this variant may respond less well to current vaccines, but more work is needed to understand this," Public Health England also said.
The two other cases of the variant in England are from the same household in South Gloucestershire. One of them had recently travelled to Brazil and has been isolating at home since returning to the UK.
Public Health England said that it is following up with all passengers on the February 10 Swiss Air flight from Sao Paulo to London via Zurich to test them and their households.
England has been under its third national lockdown since early January following the discovery of a UK variant which led to the number of cases soaring once more. The UK has the fifth-highest COVID-19 death toll in the world with more than 122,800 fatalities deplored since the beginning of the pandemic.
Prime Minister Boris Johnson unveiled a lockdown exit plan last week. Under the government's new strategy, all schools will reopen on March 8, to be followed by an easing on public gathering later in the month.
Non-essential shops, gyms and outdoor venues including beer gardens and theme parks should meanwhile be allowed to reopen their doors on April 12.
As of Sunday, more than 20 million people in the UK have received at least one dose of the vaccine. This amount to more than 30 doses administered per 100 people, according to Our World in Data. This is the third-highest rate after Israel and the United Arab Emirates.