The Omicron variant of COVID-19 has probably arrived in Germany, a minister in the western state of Hesse said on Saturday after mutations were found in a passenger arriving from South Africa.

The statement comes a day after a report saying the new coronavirus variant identified in South Africa has not yet been found in Germany but has likely spread to more countries than has so far been detected, according to an interior ministry report seen by Reuters.

It was unclear whether vaccines were less effective on the new variant or whether it made people more ill, according to the report.

"The mutation profile suggests however that we seriously have to consider the possibility that vaccines may not be as effective," it read.