Federal agents raided four Southern California museums and a Los Angeles art gallery as part of a multi-year investigation into alleged illegal smuggling of Southeast Asian and Native American artifacts. The museums targeted Thursday morning were the Los Angeles County Museum of Art, the Bowers Museum of Cultural Art in Santa Ana,the Pacific Asia Museum in Pasadena and the Mingei International Museum in San Diego. The targets of the investigation are Robert Olson, an alleged art smuggler, and Jonathan Markell, the owner of Silk Roads Gallery in Los Angeles, which also was raided.

LOS ANGELES (CBS) The search warrants gave agents the authority to search the museum’s galleries, storage areas offices and computers. According to the warrants, the men illegally smuggled looted artifactsfrom Thailand, Myanmar, China and Native American sites and sold them to Southern California art museums. Some of the museums’ curators knew the artifacts were illegally or suspiciously purchased, according to the warrants.Representatives from LACMA, Bowers and Pacific Asia museums were not immediately available for comment.

The four museums were raided shortly after 7:30 a.m. and one hour later, more than 30 federal agents, including some from the Internal Revenue Service, were on LACMA’s premises, the Los Angeles Times reported.

Other agents involved in the investigation were from U.S. Immigration and Customs Enforcement and other federal agencies, the Times reported.

According to the warrants, Olson and Markell met with an unnamed undercover agent with the National Park Service who portrayed himself to them as an eager collector of cultural artifacts.

Museum officials accepted the looted art with values inflated to help sellers obtain tax write-offs, the warrants said. The agent secretly taped 13 meetings and 110 telephone calls with Markell and his wife. During the discussions, they talked about the sale and smuggling of the looted objects, the warrants said.

Olson and Markell provided their clients with bogus appraisals that unlawfully hiked up the artifacts’ value by as much as 400 percent, according to the warrants. Their clients then donated the looted art to Southland museums, which gave them tax write-offs at the inflated value, the warrants said.

Thailand and China have strict laws banning the export of antiquities, the Times reported. Since 2003, the United States has had a ban on Myanmar imported and a federal law prohibits importing stolen objects into the United States.