An animal-rights group has filed a federal lawsuit accusing the U.S. Department of Agriculture of improperly withholding information gathered during its investigation into the near-fatal tiger attack on illusionist Roy Horn.

People for the Ethical Treatment of Animals is challenging the USDA's decision to withhold affidavits of the agency's employees and witnesses collected while it investigated alleged violations of the Animal Welfare Act and other laws.

The USDA said disclosing the affidavits would violate the witnesses' privacy, according to the complaint, which was filed Wednesday in Washington, D.C.

PETA contends the public interest in the use and treatment of exotic animals for entertainment purposes outweighs privacy concerns.

The lawsuit seeks a court order requiring the USDA to make the requested records immediately available to Norfolk, Va.-based PETA.

Horn was performing in the "Siegfried & Roy" show at The Mirage hotel-casino in October 2003 when he was mauled by a white Bengal tiger named Montecore. The attack left Horn, now 61, partially paralyzed and ended the long-running Las Vegas Strip production.

The USDA's final report — dated Sept. 28, 2004, and consisting of the Mirage hotel-casino's internal investigation, a Las Vegas police probe and witness statements — was obtained by The Associated Press in June 2005 through a Freedom of Information Act request. It showed the case was closed with no official determination of what set off the animal.

PETA also filed a FOIA request for the report and several supporting affidavits.

Its lawsuit alleges the USDA withheld affidavits from the deputy administrator of the agency's Animal Care Division, the Animal Care Division's veterinarian and a member of the audience who witnessed the attack.

"The USDA's lack of compliance with the letter and the spirit of the Freedom of Information Act is helping companies to get away with animal abuse," PETA Senior Vice President Mary Beth Sweetland said in a statement on the group's Web site.

A USDA spokesman in Washington said Friday he could not comment on a pending lawsuit.