Prague - In theory, about 100,000 Czechs could have their credit card replaced in the upcoming days after a possible personal data leak.

ČSOB, Raiffeisen, Česká spořitelna, and Volksbank CZ have started to block thousands of credit cards after it transpired that personal data may have been stolen.

According to Roman Kotlán of the Czech Bank Card Association, the measure is being adopted just to be on the safe side.

"The finances of the clients are in no way in danger. Victims of fraud will be fully compensated by the banks," said Kotlán. 

"The only thing that the cardholders may face now is a temporary blocking of their credit card," he added.

Fraudsters are believed to have stolen personal data from Spanish Visa and Eurocard/MasterCard providers. Czech banks have been warned by Visa and Mastercard about a month ago.

There is particular concern for those who have recently visited Spain.

"An extensive personal data leak has been reported in the spring and summer (in Spain). It may have been a company that processes bank transactions from payment cards terminals and ATMs," said Kotlán.

It is so far the biggest recall in the history of Czech banks.

Over 100,000 credit cards have been also recalled in Germany. It is reportedly the largest recall in German history, says German daily Financial Times Deutschland. Spain is as popular a tourist destination with the Germans as it is with the Czechs.