A man who bought a storage unit for £390 opened it to find it had a safe stuffed with £5.8million inside.
TV auctioneer Dan Dotson, who owns American Auctioneers and features on reality show Storage Wars, said a woman came up to him at a charity auction event in California to tell him the story.
In a video on Facebook, he claimed he woman told him: "My husband works for a guy and he bought a unit from you for $500 (£390) and it had a safe in it."
The man is then said to have called a locksmith to open the safe, according to the account told to website Blast.
"The first person that they called to open the safe couldn't, or didn't," said Mr Dotson on Facebook.
"They called a second person and when that person opened it up... inside the safe they're normally empty, but this time it wasn't empty.
"It had $7.5million (£5.8million) cash inside."
Mr Dotson told Blast the woman said a lawyer representing the original owners of the furniture then got in touch.
They offered the new owner £465,000 ($600,000) but he turned it down before finally negotiating a reward of £930,000 ($1.2 million).
The man who bought the storage unit handed the safe and cash back, pocketing his cut.
The identity of the lucky finder and location he bought it is not clear.
Mr Dotson also did not explain where the money came from, but asked followers on Facebook: "What would you do?" to mixed reactions.
