A man was charged Tuesday with smuggling songbirds into the United States by hiding more than a dozen of them in an elaborate, custom tailored pair of leggings during a flight from Vietnam to Los Angeles.

Sony Dong, 46, was arrested at Los Angeles International Airport in March after an inspector spotted bird feathers and droppings on his socks and tail feathers peeking out from under his pants, prosecutors said.

"He had fashioned these special cloth devices to hold the birds," said U.S. attorney spokesman Thom Mrozek. "They were secured by cloth wrappings and attached to his calves with buttons."

Authorities later linked Dong's scheme to Duc Le, who was arrested after investigators searched his Orange County home and found 51 songbirds in an outdoor aviary. Both are charged with conspiracy in an eight-count federal indictment.

The songbirds sell for $10 to $30 in Vietnam and are sold to collectors in the United States for about $400, Mrozek said.

"They're rare and there are collectors who are willing to pay top dollar for these things," he said.

U.S. Fish and Wildlife inspectors flagged Dong for inspection because he had abandoned a suitcase containing 18 birds at the Los Angeles airport in December, Mrozek said. Five of the birds died in transit.

Dong returned to Vietnam in February to pick up more birds and returned a month later with three red-whiskered bul-buls, four magpie robins and six shama thrush under his pants, prosecutors said.

The birds are now in quarantine and could be donated to a zoo if they are healthy.

Fish and Wildlife officials said the bul-buls are listed as an injurious species, which means they pose a threat to people, native wildlife or the ecosystem.

"With anything coming from Southeast Asia, the big concern is the possibility that the birds are infected by avian flu," Mrozek said.

Le and Dong have been released on bail. Messages left with their public defenders were not returned Tuesday night.