Somehow, a small number of them found their way into the hands of collectors - and all that were found and confiscated (they were property of the mint, and counterfeit coins, because no '33 Double Eagles were ever issued) traced were determined to have come through unscrupulous coin deal Israel Switt, through the Head Mint Cashier or Switt's contact in the mint, George McCann. McCann has already been convicted for a similar theft while serving at the mint.
What complicated the theft was that King Farouk of Egypt purchased a '33 Double Eagle om 1944 and applied for an export license. Customs officials had no idea that '33 Double Eagles were considered U.S. property, ineligible for export.
After Farouk's death, the coin appeared an auction catalogue for his massive collections of . . . everything. The U.S. Government sought repossession of the '33 Double Eagle, the item was removed from the auction and disappeared. It appeared again. It turned up again in possesion of an English coin dealer in 1996.
In 2001. the case was settled, transferring title to the U.S., with the U.S. agreeing to make that singular '33 Double Eagle the only one every issued by the U.S. It was sold act auction for over $6 million and the U.S. and the English coin dealer split the profits. In 2005, the ancestors of Israel Skitt anounced they had found ten mint-condition '34 Double Eages in a safe deposit box. The jury in a U.S. District Court tial unanimously found that the coins had never been issued by the mint and were not the property of Switt's heirs. This was upheld by a Federal Appeals Court.
A good book on this subject, although it was written before completion of the ten 'new' Switt safe deposit coins, is Alison Frankel: The Epic Story of the World's Most Valuable Coin.
My story about was a truncated version of a fascinating and detaiied story.
Are you sure they weren’t pattern coins? Not “real”, but test types.