Credit Suisse under scrutiny for aiding tax evasion

WASHINGTON (CNNMoney) Bankers helping customers buy gold bars to store in Swiss bank safes. A wealthy customer who traveled on flights hiding $250,000 in pantyhose to stash in Swiss accounts.

U.S. prosecutors say they have evidence like this to support their case that bankers at Credit Suisse Group helped U.S. customers evade taxes on at least $4 billion in hidden assets.

Investigations are heating up for Credit Suisse, the Swiss banking giant.

The Senate's Permanent Subcommittee on Investigations scheduled a hearing for next Wednesday that would focus on the alleged practices. It didn't name the bank that would be in focus, but sources familiar with the matter identified it as Credit Suisse.

The hearing is designed in part to help invigorate slow-moving settlement talks. People familiar with the talks say Credit Suisse has discussed a settlement of about $800 million.

But some U.S. officials are pushing for a tougher line. U.S. guidelines for failing to report foreign bank accounts call for penalties of 50% of the account values. In the Credit Suisse case, that would mean $2 billion.

In 2009, UBS, another Swiss bank, paid $780 million to settle similar charges. But that came at the time of the global financial crisis -- UBS was struggling and U.S. and Swiss banking regulators asked for a lighter penalty to avoid unsettling markets.

Credit Suisse is now in far healthier shape than UBS was and could absorb a bigger penalty, some U.S. officials believe.

Credit Suisse and the Justice Department declined to comment. Credit Suisse has previously said it is cooperating with the investigation.

The landmark UBS case helped crack vaunted Swiss bank secrecy, prompting some customers to move accounts and others to reach settlements with the IRS.

Documents filed by prosecutors allege that even as the Justice Department's probe of UBS was ongoing, Credit Suisse bankers were helping customers move their money from UBS into other b! anks to escape the reach of U.S. authorities. Eight Credit Suisse bankers have been charged, and all remain at large, believed to be in Switzerland.

In all, 14 Swiss banks are under criminal investigation.

The U.S. has also said about 100 Swiss banks have signaled their intent to come clean about accounts they were hiding for U.S. customers under a program that promises leniency in exchange for cooperation.

"The Department of Justice has put more pressure on the Swiss banks in the past six years than they have for the previous six decades," says Nathan Hochman, former assistant attorney general for the Justice Department's tax division.

Still, the long-running investigations have been dragging, causing frustration for some lawmakers and investigators. The clock is ticking more loudly now, because U.S. authorities have six years after a tax violation to bring charges.