The California couple who found $10 million in gold coins buried in their backyard last year may be forced to give up the entire stash as the coins may have been stolen from the U.S. Mint in 1900. If true, that means the coins are the property of the U.S. government.

As TheBlaze recently reported, the unidentified couple already learned that they would have to pay about half of the $10 million value of the coins in federal and state income taxes. Now they could potentially walk away with nothing after their monumental find.

The value of the "Saddle Ridge Hoard" treasure trove is estimated at $10 million or more. (AP/Saddle Ridge Hoard discoverers via Kagin's, Inc.)

The value of the “Saddle Ridge Hoard” treasure trove is estimated at $10 million or more. (AP/Saddle Ridge Hoard discoverers via Kagin’s, Inc.)

The San Francisco Chronicle reportedly obtained an old news article from California fishing guide Jack Trout, who is also a historian and collector of rare coins. The news clipping from Jan. 1, 1900, describes a gold heist from the San Francisco Mint, which some think just might explain the discovery of the $10 million in coins.

More from the report:

In addition, the coins were largely in chronological order, which indicates they were unused. (There are some problems with this theory, though, according to The Chronicle’s Kevin Fagan in an article summarizing the various hypotheses). Kevin noted that one-third of them were unused, and the chronological order was that they spanned nearly 50 years in date.

New information, which adds credibility that the heist was an inside job at the Mint, became available late Monday afternoon from research by historian Jack Trout: An 1866 Liberty $20 gold piece — which did not include the words “In God We Trust” — was part of the haul, a coin that alone is worth more than $1 million.

“This was someone’s private coin, created by the mint manager or someone with access to the inner workings of the Old Granite Lady (San Francisco Mint),” Trout said. “It was likely created in revenge for the assassination of Lincoln the previous year (April 14, 1865). I don’t believe that coin ever left The Mint until the robbery. For it to show up as part of the treasure find links it directly to that inside job at the turn of the century at the San Francisco Mint.”

The couple shouldn’t panic yet though. After all, the theory is still exactly that — just a theory.

In a statement to ABC News, San Francisco Mint spokesperson Adam Stump said: “We do not have any information linking the Saddle Ridge Hoard coins to any thefts at any United States Mint facility. Surviving agency records from the San Francisco Mint have been retired to the National Archives and Records Administration (NARA), under Record Group 104. Access to the records is under NARA’s jurisdiction: http://www.archives.gov/.”