New Delhi, Nov 26 (IANS): The first European case of the new ultra-infectious and vaccine-resistant Botswana variant has been confirmed in Belgium, with experts in the UK warning that it could be there already, the Daily Mail reported.

Passengers flying to the Netherlands from South Africa were barred from getting off the plane on Friday as the continent tightened its borders in an attempt to shut out the strain, which scientists have described as the 'worst variant ever'.

Yet, British arrivals from the variant's epicentre, Johannesburg, were left to mingle with hundreds of other passengers as they flew into Heathrow on the last flights out of Africa before the red list was re-imposed at midday. Passengers revealed they were not tested or questioned about their travel history, the report said.

In a sombre statement to MPs in the House of Commons on Friday morning, the UK Health Secretary said the new B.1.1.529 strain -- which has been spotted in Europe -- posed a 'substantial risk to public health' and described its ultra-transmissibility and vaccine-dodging abilities as of 'huge international concern'.

Adam Finn, a member of the Joint Committee on Vaccination and Immunisation (JCVI), had earlier raised the prospect of lockdown curbs being reintroduced, warning that people must be braced for a 'change in restrictions' if the variant spreads to the UK, the report added.

Susan Hopkins, chief medical advisor to the UK's Health and Security Agency (UKHSA), warned that it is 'possible' that the strain has already entered Britain.

She said "people are arriving every day" to the UK from Belgium, South Africa, Botswana, Hong Kong and Israel, where the variant has been officially detected.

Around 10,000 people have arrived from South Africa alone in the last two weeks since the strain was first detected, the report added.