A 70-million-year-old dinosaur skeleton from the Gobi Desert that was smuggled to the United States in pieces and auctioned for more than $1 million was returned on Monday by the US government to Mongolia.

The huge Tyrannosaurus bataar's skull was on display at a repatriation ceremony near the United Nations in New York, where officials of the US Attorney's Office in Manhattan and the US Immigration and Customers Enforcement (ICE) formally turned over the nearly complete skeleton to Mongolian officials.

Mongolia demanded the return of the 8-foot-tall (2.4 meter), 24-foot-long (7.3 meter), mostly reconstructed cousin of the Tyrannosaurus rex last year after commercial paleontologist Eric Prokopi sold it at a Manhattan auction last spring for $1.05 million.

Prokopi, based in Gainesville, Florida, bought and sold whole and partial fossilized dinosaur skeletons.

US authorities filed charges against Prokopi in October and seized the skeleton, which is comprised of fossilized bones welded to a metal frame.

"This is one of the most important repatriations of fossils in recent years," ICE Director John Morton said in a statement. "We cannot allow the greed of a few looters and schemers to trump the cultural interests of an entire nation."

Morton said the repatriation would "undo a great wrong by returning this priceless dinosaur skeleton to the people of Mongolia."    

Mongolian President Tsakhia Elbegdorj thanked US prosecutors, judges, investigators and paleontologists in a statement: "Our two countries are separated by many miles, but share a passion for justice and a commitment to putting an end to illegal smuggling."

In addition to the skeleton, the United States is also helping to return more fossils to Mongolia, Manhattan US Attorney Preet Bharara said.

The Tyrannosaurus bataar lived some 70 million years ago in what is now Mongolia, and its skeleton was discovered in 1946 in a joint Soviet-Mongolian expedition to the Gobi Desert, according to court and federal documents.

It was imported to the United States in 2010 from Great Britain, with customs documents that falsely claimed it originated in Great Britain and was valued at $15,000, far below its auction price.