The National Rifle Association has hired private investigators to track down hundreds of gun owners whose firearms were seized by New Orleans police in the aftermath of Hurricane Katrina, according to court papers filed this week.

The NRA is trying to locate gun owners for a federal lawsuit that the lobbying group filed against Mayor Ray Nagin and Police Superintendent Warren Riley over the city's seizure of firearms after the Aug. 29, 2005, hurricane devastated New Orleans.

In the suit, which is set for trial in February, the NRA and Second Amendment Foundation claim the city violated gun owners' constitutional right to bear arms and left them "at the mercy of roving gangs, home invaders, and other criminals" after Katrina.

The NRA says the city seized more than 1,000 guns that weren't part of any criminal investigation after the hurricane. Police have said they took only guns that had been stolen or found in abandoned homes.

In April 2006, police made about 700 firearms available for owners to claim if they could present a bill of sale or an affidavit with the weapon's serial number.

In court papers filed Monday, NRA attorneys say investigators have found few of the guns' owners because the storm has scattered so many residents.

A trial for the case is scheduled to open Feb. 19, but the NRA is asking U.S. District Judge Carl Barbier to postpone it.

"Since a primary objective of this litigation is to cause the return of seized firearms to their lawful owners, more time is necessary to locate them," NRA lawyers wrote.

Barbier had not yet ruled on the request Wednesday.

Alan Gottlieb, founder of the Bellevue, Wash.-based Second Amendment Foundation, said the police department only has returned roughly 100 of the 1,000 seized guns.

"Obviously, we don't expect the city to find everybody. We only wanted to see a good-faith effort, and that's what the city didn't do," Gottlieb added. "It's a bad example to let them get away with it."

Attorneys for the NRA and city didn't return a reporter's telephone calls Wednesday.

In August 2006, Barbier refused to dismiss the lawsuit at the city's request. The city had argued that the plaintiffs couldn't show that federal law applies to their claims against city officials.

"The flaw in the NRA's argument is that the Second Amendment applies against only the federal government; it does not apply to the States through the Fourteenth Amendment because the right to keep and bear arms has never been recognized as a fundamental individual right," city attorney argued in court papers.