ZURICH, SWITZERLAND - Credit Suisse (CSGN.VX) clients may have lost up to 1 billion Swiss francs ($925.9 million) on investments connected to accused swindler Bernard Madoff, newspaper Sonntag reported on Sunday.

Without giving details of its sources, Sonntag reported that internal forecasts at Credit Suisse showed that customers of Switzerland's second-largest bank could have lost 0.9-1.0 billion francs in the Madoff case.

Credit Suisse spokesman Jan Vonder Muehll said: "Credit Suisse did not actively recommend or sell products invested with Bernard Madoff.

"Furthermore, none of the funds of hedge funds offered by Credit Suisse contained holdings in Madoff funds."

Authorities say Wall Street fund manager Madoff has confessed to running a $50 billion fraud that ensnared investors and charities around the world.

Funds managed by Swiss banks have been prominent victims of Madoff, who is accused of running a global Ponzi scheme in which earlier investors are paid off with investments from newer clients.