The nearly complete Tyrannosaurus bataar skeleton was imported from Great Britain to Gainesville, Fla., in March 2010 with erroneous claims that it originated in Great Britain and was worth only $15,000, according to the lawsuit filed in U.S. District Court in Manhattan.
It sold at auction on May 20 for more than $1 million even though Mongolia's president had obtained a temporary restraining order from Texas State Civil District Judge Carlos R. Cortez prohibiting its auction, the suit said. The completion of the sale was made contingent upon the outcome of any court proceedings. The suit did not identify the buyer.
James T. Hayes Jr., head of the U.S. Immigration and Customs Enforcement's Homeland Security Investigations in New York, said criminal smugglers misrepresented the fossil to customs officials when they illegally imported it into the United States.
Jim Halperin, cofounder of the The Heritage Auctions, a defendant in the lawsuit, said: "We auctioned the Tyrannosaurus bataar conditionally, subject to future court rulings, so this matter is now in the hands of lawyers and politicians."
He added: "We believe our consignor purchased fossils in good faith, then spent a year of his life and considerable expense identifying, restoring, mounting and preparing what had previously been a much less valuable matrix of unassembled, underlying bones. We sincerely hope there will be a just and fair outcome for all parties."
U.S. Attorney Preet Bharara said in a news release that the skeletal remains are "of tremendous cultural and historic significance to the people of Mongolia, and provide a connection to the country's prehistoric past. When the skeleton was allegedly looted, a piece of the country's natural history was stolen with it, and we look forward to returning it to its rightful place."
The release included a quote from Tsakhia Elbegdorj, Mongolia's president, saying he was thankful for the legal action to recover the skeleton, calling it "an important piece of the cultural heritage of the Mongolian people."
He added: "Cultural looting and profiteering cannot be tolerated anywhere and this cooperation between our governments is a large step forward to stopping it."
The lawsuit said the dinosaur's remains were believed to have been discovered in the Gobi Desert between 1995 and 2005. An auction house catalog listing of the skeleton said it measures 24-feet long and 8-feet tall, the suit said.
A June 5 examination by at least five experts specializing in bataars resulted in unanimous agreement that the skeleton was a Tyrannosaurus bataar and almost certainly originated in the Nemegt Basin in Mongolia.
One expert, Khishigjav Tsogtbaatar, head of Paleontological Laboratory and Museum in Mongolia, said in a document filed with the lawsuit that it appeared some part of the skeleton's skull and postcranium were destroyed by poachers who lacked professional knowledge about proper excavation techniques.
U.S. authorities said Tyrannosaurus bataars were first discovered in 1946 during a joint Soviet-Mongolian expedition to the Gobi Desert in the Mongolian Omnogovi Province. Since 1924, Mongolia has enacted laws declaring fossils to be the property of the government of Mongolia and criminalizing their export from the country.
GET THE LATEST NATIONAL AND INTERNATIONAL NEWS FROM ABCNEWS.COM ---
Get Eyewitness News Delivered