The U.S. Mint seized 10 Double Eagle gold coins from 1933, among the rarest and most valuable coins in the world, that were turned in by a jeweler seeking to determine their authenticity.

David Lebryk, acting director of the Mint, announced in a news release that the rare coins, which were never put in circulation, had been taken from the Mint "in an unlawful manner" in the mid-1930s and now were "recovered."

The coins, which are so rare that their value is almost beyond calculation, are public property, he said.

But Joan S. Langbord plans a federal court lawsuit to try to recover them. She recently found the coins among the possessions of her father, longtime Philadelphia jeweler Israel Switt. The family lawyer said Langbord notified the Mint of the discovery in September. Mint officials asked to authenticate the coins and then confiscated them after doing so, said the lawyer, Barry H. Berke. He said Mint officials could not prove that the coins had been stolen or were subject to forfeiture.

Double Eagles were first minted in 1850 with a face value of $20. The 445,500 coins minted in 1933 were never put into circulation because the nation went off the gold standard. All the coins were ordered melted down, but a handful are believed to have survived, including two donated to the Smithsonian Institution.

In 2002, Sotheby's and numismatic firm Stack's auctioned off a 1933 Double Eagle coin for $7.59 million, the highest price ever paid for a coin. That Double Eagle, which is believed to have been part of a collection belonging to King Farouk of Egypt, surfaced when a coin dealer tried selling it to undercover Secret Service agents. After a legal battle, the dealer was permitted to sell the coin at auction on the condition that he split the proceeds with the Mint.

The Mint said officials were still deciding what they would do with the newly seized coins, which are being held at Fort Knox in Kentucky. They said they had no plans to auction them but would consider saving "these historical artifacts" for public exhibits. Other seized Double Eagle coins were melted down.

The Mint contends Switt obtained a cache of the gold coins from his connections at the Mint just before they were to be reduced to bullion in 1937.