Los Angeles: A coin dealer handling a $US10 million ($A11.21 million) treasure trove found by a US couple has dismissed a report that the hoard may have been stolen and must be given back.
The California couple uncovered eight cans filled with more than 1400 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 specialising in ancient coins, Kagin's, 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 January 1, 1900, referring to the recent theft which it said mostly involved mint, with an overall face value of up to $US27,000 - similar to the Saddle Ridge trove.
If proven to be from the San Francisco Mint, the coins might be the property of the government and have to be handed back, according to an ABC online report.
However, Kagin boss Donald Kagin said 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 $US20 gold coins - whereas the Saddle Ridge hoard also had $US10 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 hoard are. Many others are circulated coins, struck over a long period of time and clearly buried over a long period of time."
He also pointed to a statement from the US 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 US Mint facility."
Kagin said plans to sell the Saddle Ridge hoard in about two months remain in place.
Kagin, whose family has been in the rare-coin business for 81 years, has previously say little about the lucky couple other than that they are husband and wife, are middle-aged and have lived for several years on the rural property in California's Gold Country.
One of the largest previous finds of gold coins was $1 million worth uncovered by construction workers in Jackson, Tennessee, in 1985. More than 400,000 silver dollars were found in the home of a man who died in 1974 and were later sold intact for $US7.3 million.