The new Covid variant Omicron has been found in Germany and the Czech Republic as the worrying mutation spreads across Europe.
A minister said it had "probably" arrived in Germany after mutations were found in a passenger arriving from South Africa.
Kai Klose, a social affairs minister in Hesse which is home to Frankfurt airport tweeted: "Last night several Omicron-typical mutations were found in a traveller returning from South Africa."
The airport is one of the biggest transport hubs and one of Europe's busiest airports.
Full sequencing of the variant is being carried out and the infected person is isolating.
The minister urged anyone who had travelled from South Africa in the last few weeks to limit contacts and get tested.
Omicron has been found while Germany and many other European countries are grappling with a surge in coronavirus cases with some enforcing restrictions.
Germany recorded 67,125 new coronavirus cases on Saturday and more than 100,000 people have died with Covid-19.
It has declared South Africa a virus-variant area which means airlines are allowed to fly only Germans to the country from South Africa.
Even vaccinated people must spend 14 days in quarantine in the country.
This comes as Dutch health officials said earlier they had detected 61 Covid cases among people who flew from South Africa on Friday.
Experts are trying to establish whether any of those who caught the virus were infected with the new Omicron variant which has emerged as fresh strain.
Those who tested positive for then new strain have been put in isolation at a hotel near Schiphol airport.
The passengers were among 600 travellers who were held for several hours after arrival while they were tested.
Dutch authorities are carrying out more testing to identify cases of Omicron, named on Friday as a variant of concern by the the World Health Organization.
The Czech Republic, meanwhile, is examining a suspected case of the Omicron variant of the coronavirus.
It was found in a person who spent time in Namibia, the National Institute of Public Health said.
Spokesman Stepanka Cechova, said in a statement: "A lab is checking a possible find of a positive specimen of the Omicron variant.
"We are awaiting confirmation or refutation of the case."
The Mirror told yesterday how the race is on to trace cases of the “most worrying” Covid-19 variant in Britain yet, as experts warned of possible restrictions this Christmas.
The UK Health Security Agency admitted B.1.1.529, which has an unprecedented 32 mutations, may already have arrived after Belgium said it had been found in a woman who had visited Egypt.
