Last year, workers replacing wood paneling moved the unlocked case into a side room.
The tusks disappeared between Aug. 12 and Aug. 27.
On Wednesday, D.C. police publicized the theft for the first time, released a photo and asked for the public’s help in locating what are once again recognized as treasured artifacts.
“This is a presentation of a great African to the United States . . . an important gift to the citizens of the city,” said Tamrat Medhin, an Ethiopian community leader who led the effort to display the tusks seven years ago. “This has to be kept for them.”
The market for ivory is thriving around the world, prompting a renewed push by federal law enforcement authorities here and abroad to target traffickers and save elephants from being killed for their tusks.
D.C. police estimated the stolen tusks to be worth at least $10,000. The Wilson Building is on Pennsylvania Avenue NW, three blocks from the White House.
The Convention on International Trade in Endangered Species banned the sale of ivory harvested after 1989.
It is legal in the United States to sell ivory obtained before then, creating two markets that authorities say make it difficult to distinguish between what was obtained legally and illegally. The price of ivory has risen, and it sells for about $1,500 a pound.
Edward Grace, deputy chief of law enforcement for the U.S. Fish and Wildlife Service, which last year crushed six tons of ivory seized in U.S. criminal investigations, said the tusks stolen from the District “would be pretty easy to sell,” adding that “it would be very hard for a police agency to stop that sale or investigate it.” Grace said trading elephant tusks is unusual in the United States, a market that he said was more interested in ornate carvings.
D.C. Council Chairman Phil Mendelson (D) said he did not know that the display case was unlocked and that the tusks were a gift from the Ethiopian emperor.
“In hindsight, if I’d realized the value of them, and I don’t necessarily mean monetary value, I would have assured there was more care in handling them,” he said.
The chairman said investigators asked that the matter be kept quiet for a time in case the thief tried to sell the tusks.
Council member Jim Graham (D-Ward 1), who worked with the Ethiopian businessman to put the tusks back on display, said the theft should have been disclosed earlier. He said police told him that they reviewed surveillance footage and lifted fingerprints from the case but couldn’t make a match.
Gwendolyn Crump, chief spokeswoman for the D.C. police, said the theft was not kept hidden, citing a publicly available police report.
She said police had lacked a clear photograph of the tusks.
“When we received the images, we released them to the public to see if we could get any leads,” she said.