The skeleton, of a roughly 8-foot tall and 24-foot long dinosaur was on display at the Cadogan Tate Fine Art after being sold at Heritage Auctions for $1.05 million last month.

According to court papers, the Government claimed that the skeleton was moved from Great Britain to Gainesville, Fla. in March 2010, with erroneous papers that claimed its origin to be in Great Britain and worth a meager $15,000.

However, experts claim, after viewing the remains that the skeleton was a Tyrannosaurus bataar and originated in the Nemegt Basin in Mongolia, not Great Britain. The skeleton can be estimated to be unearthed 17 years ago.

Eric Prokopi, a Florida dealer of fossils who acquired the remains and constructed the skeleton denied the government's claim.

Prokopi reportedly said: "I can wholeheartedly say the import documents are not fraudulent, a truth I am confident will be brought to light in the coming weeks. The value was declared much lower than the auction value because, quite simply, it was loose, mostly broken bones and rocks with embedded bones. It was not what you see today, a virtually complete, mounted skeleton."

But documents have been filed on Monday in US District Court in New York against the illegal papers.

 A Manhattan prosecutor filed to seize the reconstituted skeleton Monday and return it to Mongolian authorities, who had tried in vain to prevent the sale.

 Mongolian President Tsakhia Elbegdorj had reasons to celebrate Monday at the legal proceedings.

 "We are one step closer to bringing this rare tyrannosaurus bataar skeleton back home to the people of Mongolia," he said. "Today we send a message to looters all over the world: We will not turn a blind eye to the marketplace of looted fossils."

However it is tough to say when the remains would be handed over to Robert Painter, a lawyer representing Mongolia.