It's another public relations debacle for the nation's museum industry, already tarred by reports that top institutions knowingly dealt in looted Italian artifacts.

Federal agents raided several Southern California museums on Thursday, mostly in search of artifacts allegedly taken from Thailand's Ban Chiang archeological site, one of the most important prehistoric settlements ever discovered in Southeast Asia. Authorities believe they were smuggled into the U.S. and donated at inflated prices so collectors could claim fraudulent tax deductions.

Court documents say a 79-year-old smuggler involved in the scheme boasted to an undercover agent that he had more items from Ban Chiang than Thailand itself did. He said he was being sent the items as they were being dug up, in violation of Thai and international law.