The No Doubt archives suffered a loss this week when the dress Gwen Stefani wore on the cover of Tragic Kingdom, the band's 1995 breakthough LP, was stolen from the Orange County, California, museum where it was on temporary display.

The red vinyl dress was reported stolen from the Fullerton Museum Center on Tuesday, where it was a part of the exhibit "The Orange Groove: Orange County's Rock n' Roll History," which runs through May 22. According to a statement released by the band's label, the dress was likely stolen between 2:30 and 3:30 p.m. PT on Tuesday.

The dress was on a mannequin and mounted on a stage three-and-a-half feet high that was surrounded by plexiglass.

"It probably would have taken two people: one as a lookout, one to take it," said Sergeant Steve Matson of the Fullerton Police Department. "We're focusing in on possibly two females that may have been involved, and we're in the process of taking yearbooks to people who work at the museum to see if they can identify them."

"Someone must have given this some thought to vault [the stage] during daylight business hours," said "Orange Groove" curator Jim Washburn. "We're trying to figure out how this was accomplished. It's awfully selfish, almost sociopathic, to think that your interest in the band matters more than anyone else who would want to see it," he said.

Stefani's dress was a central item in the exhibit, which celebrates the musical legacy of the O.C. and coincides with the 50th anniversary of the Fender Stratocaster guitar, which was created in Fullerton. Other No Doubt items in the collection are band photos, instruments and awards, including their 2003 Grammy for "Underneath It All" and 1997 MTV Video Music Award for "Don't Speak."

Guitars from the Offspring, Mike Ness of Social Distortion (whose axe was featured on the cover of the band's 1990 self-titled album) and items from the O.C.'s folk, hippie and punk scenes are also included.

The theft of Stefani's dress -- which had been on loan to the Hard Rock Café in the past -- marks the first time anything has been stolen from the museum in 17 years, according to Washburn. The museum decided to publicize the robbery on Tuesday in hopes that it would expedite the return of the dress.

"Our foremost priority in this matter is the safe return of the dress, as it means a lot to the band," Interscope Records said in the statement.

The Fullerton Police Department is currently investigating the theft, but the label has asked that anyone with information on the whereabouts of the dress contact the police department at (714) 738-5336 -- or return it to the museum's after-hours drop-off box, "no questions asked."

[This story was updated at 4:28 p.m. ET on 01.12.2005]