ZURICH (Reuters) - U.S. authorities are ratcheting up pressure on Credit Suisse CSGN.VX to plead guilty to helping wealthy Americans hide untaxed money in Swiss bank accounts, Swiss newspaper NZZ am Sonntag said.

Swiss bank Credit Suisse logo is seen in front of its headquarters in Zurich May 2, 2014. REUTERS/Arnd Wiegmann

The source quoted by the newspaper said U.S. authorities had made “extreme” demands regarding potential fines and wanted the names of all U.S. citizens who had stashed away untaxed money in Credit Suisse accounts, NZZ am Sonntag said.

“Washington is asking for a guilty plea,” the newspaper said on Sunday, quoting an unnamed source close to the bank.

Contacted by phone, a spokesman for the bank declined to comment.

Credit Suisse is one of over a dozen Swiss banks under criminal investigation in the United States over whether and how they helped wealthy Americans dodge tax. Pressure on Credit Suisse increased this week as one of its former employees pleaded guilty to helping U.S. clients avoid taxes.

Swiss Finance Minister Eveline Widmer-Schlumpf met U.S. Justice Minister Eric Holder in Washington on Friday to discuss the tax row, saying she sought fair and equal treatment of Swiss banks in the probe. No specific results of the meeting have been announced.

Swiss bank secrecy laws bar banks from revealing the names of account holders, but Swiss authorities made an exception in 2009 when they handed over data on U.S. clients of Credit Suisse's national rival UBS UBSN.VX to U.S. authorities to stop them issuing an indictment against the bank.

Swiss newspaper Schweiz am Sonntag said in an article on Sunday Credit Suisse was urging the Swiss government to consider using emergency law if no other solution could be found, quoting unnamed sources.

The Credit Suisse spokesman declined to comment on this report too.

Switzerland’s private banking model has been rattled to its core by the U.S. crackdown on tax evasion. UBS has admitted to helping U.S. taxpayers evade taxes and paid a $780 million fine in 2009.

Last month, Credit Suisse said it doubled its provisions for tax and securities law matters in the United States to 895 million Swiss francs ($1 billion).