SAN FRANCISCO — A federal judge has set off a free-speech tempest after shutting down a U.S. Web site for posting internal documents accusing a Cayman Islands' bank branch of money laundering and tax-evasion schemes.

The Bank Julius Baer & Co. said in papers filed in U.S. District Court in San Francisco that a disgruntled executive fired for "misconduct" stole the documents and illegally posted them on Wikileaks.org. The bank also said a number of the documents have been altered, but it didn't provide details.

The site claims to have posted 1.2 million leaked government and corporate documents that it says expose unethical behavior, including a 2003 operation manual for the U.S. prison at Guantanamo Bay, Cuba.

The bank, based in Zurich, sued Wikileaks and its San Mateo hosting company Dynadot on Feb. 6, alleging the Web site had posted stolen and confidential financial data.

On Feb. 14, Dynadot agreed to shut down the site and bar Wikileaks from transferring the domain name to another host. U.S. District Judge Jeffrey White issued a formal ruling the next day. Dynadot officials didn't return telephone calls yesterday.

"This is akin to seizing all the copies of the New York Times, locking the doors and ordering the landlords not to let anyone back in the building," said Julie Turner, a Palo Alto Internet attorney who briefly represented Wikileaks, but not during last week's hearing in front of White. Wikileaks was not represented at that hearing.

Wikileaks said in a statement that shutting down the entire Web site — instead of narrowly ordering the removal of the disputed materials — amounts to unconstitutional "prior restraint" by the government of an entire publishing organization.

Wikileaks vowed to continue publishing the bank's documents on its other Web sites hosted by companies outside the United States. Wikileaks' Web site says it was launched by Chinese dissidents, journalists and others, but it's unclear where the organization is based.

"The order is clearly unconstitutional and exceeds its jurisdiction," Wikileaks spokesman Julian Assange said in the e-mail statement issued from Paris on Feb. 18. "Wikileaks will keep on publishing. In fact, given the level of suppression involved in this case, Wikileaks will step up publication of documents pertaining to illegal or unethical banking practices."

David Ardia, an Internet speech expert at Harvard Law School, said a court had never before ordered an entire Web site shut down over a document dispute. He said it struck a nerve.

"This is a prior restraint in the most extreme fashion," Ardia said. "This is a judge who doesn't have a good understanding of the Internet."

The judge has scheduled more arguments on the issue for Feb. 29.