A couple found 1,400 gold coins in an area known for buried treasure since the Gold Rush in the 19th century.
A dealer handling a $10 million treasure trove found by a U.S. couple dismissed Tuesday a report that the horde may have been stolen and therefore have to be given back.
The California couple uncovered eight cans filled with more than 1,400 coins on their property, in what is believed to be the most valuable treasure trove ever discovered in the United States.
They took them to a firm specializing in ancient coins, Kagin's Inc, which valued them and announced last week that they will sell them, via online retail giant Amazon.
But on Monday the San Francisco Chronicle linked the find -- called the Saddle Ridge Treasure trove -- to a robbery at the San Francisco Mint.
It published a newspaper report from Jan. 1, 1900, referring to the recent theft which it said mostly involved mint, uncirculated coins, with an overall face value of up to $27,000 -- similar to the Saddle Ridge trove.
If proven to be from the U.S. Mint, the coins might be the property of the government and have to be handed back, according to an ABC news online report.
Kagin Inc boss Donald Kagin however told AFP he was "very confident" that the Saddle Ridge trove was not linked to the San Francisco Mint theft.
"There's a number of reasons why they can't possibly be" connected, he said.
He cited records from the time of the San Francisco theft suggesting it involved five canvas sacks filled with $20 gold coins -- whereas the Saddle Ridge horde also had $10 and other coins.
In addition the stolen coins "would have all been mint state, recently struck coins," he said.
"But only some of the coins in the Saddle Ridge horde are. Many others are circulated coins, struck over a long period of time and clearly buried over a long period of time.
"The only parallel here is the similar (face) value. But again, not even that's that close because of the different denominations," he said.
He also pointed to a statement from the U.S. Mint in Washington, sent to him in an email, which said: "We do not have any information linking the Saddle Ridge Hoard coins to any thefts at any U.S. Mint facility."
Kagin said plans to sell the Saddle Ridge hoard in about two months remain in place.
Asked if he could guarantee to the couple, named only as John and Mary, that there would be no hitches in the sale, he said: "Nobody can guarantee anything.
"But we are absolutely on our timeline with Amazon.com and kagins.com, to be selling these coins sometime in May," he added.
Kagin said he had been in the business for 46 years, and was used to claims about discovered treasure troves.
"When anything like this is found or discovered you get people from all over suggesting that it might be theirs, or their great grandfather's, or it would have been stolen, or bank heist.
"You get all sorts of bizarre scenarios that people are absolutely sure are true. But in this case we did our due diligence, we checked these things out and we have found them to be bogus."
The Saddle Ridge Treasure is named after a feature on the couple's property in an area of northern California known for buried treasure since the Gold Rush in the 19th century.
The couple said they were simply taking their dog for its daily walk when they made the first find.
"I never would have thought we would have found something like this. However, in a weird way I feel like I have been preparing my whole life for it," said Mary last week.