Up to $1 million in Asian artwork stolen from The Walters Art Gallery has been discovered in a museum guard's basement, authorities say.

Gregory Bartgis, 30, a museum security supervisor, was arrested at his home Tuesday, said FBI agent James Dearborn.Bartgis was charged Wednesday with theft, punishable by up to 15 years in prison, said police Lt. Lawrence Leeson. Federal charges were not filed because the items did not leave the state, the FBI said. A bail hearing was expected later today.

All 81 items reported stolen from the gallery Aug. 16 appear to have been recovered, said Joseph Corless, agent in charge of the FBI office in Baltimore.

"It looks like we've recovered all the items, plus some additional items we located that hadn't been reported stolen as yet," said Leeson.

The artwork includes jade, Chinese snuff bottles, figurines, incense burners, boes and an 18-inch porcelain vase dating to the 18th century known as the Peach Bloom Vase. The pieces were valued at between $500,000 and $1 million.

Law enforcement agents found the art in boxes in Bartgis' basement, Leeson said. None of the artifacts appeared to have been sold, he said.

The theft from at least 13 plexiglass display cases on the museum's fourth floor was discovered after the curator returned from vacation. Other pieces in the cases had been rearranged to hide the theft, a museum spokesman said.

The theft was "very sophisticated and well planned" and obvious only to those who knew the collection well, museum spokesman Howard White said last week.