Jul. 8, 2009 (United Press International) -- A new U.S.-Swiss treaty on bank secrecy may not help the Internal Revenue Service catch tax evaders, a Swiss official says.

Swiss Vice President Doris Leuthard said under the amended treaty, the United States will have to supply the names of suspected tax evaders to obtain information about their Swiss bank accounts, The Washington Post reported Wednesday.

"This is basic, basic information they will need to give us," Leuthard said.

But U.S. authorities don't necessarily have the names, the Post reports.

Attorney Jack Blum, who specializes in international tax and money-laundering matters, said he doesn't think the change will solve the problem.

The U.S. government has asked a federal court to order Switzerland's largest bank, UBS (NYSE:UBS) , to turn over the names of thousands of Americans suspected of hiding money from the IRS.