The northwest Spanish town of La Coruña posted a lost-and-found notice this week that has captured the world's attention.
"FOUND: A lottery ticket bought more than a year ago, which entitles the owner to an unclaimed $6.3 million jackpot."
"LOST: The ticket's owner."
Manuel Reija Gonzalez found the unclaimed lottery ticket from 2012 in a lost property box at the lottery kiosk where he worked.
Its worth: 4.7-million euro.
Instead of claiming it for himself, the honest man turned it into authorities.
"I never for a moment thought about keeping it because I wanted to be able to sleep well at night with a clear conscience," Gonzalez told the BBC.
"Because here was somebody who had a problem forgetting his ticket and I put myself in his shoes, and it's the sort of thing I could have done. I thought the best thing to do was just to return the ticket," he added.
According to the newspaper La Voz, someone bought the ticket with the winning numbers 10, 17, 24, 37, 40 and 43 from a shopping centre in Galicia, Spain, but managed to misplace it.
Gonzalez assumed the ticket, which was not purchased at his kiosk, fell out of someone's wallet.
When he ran the numbers, he was shocked to learn of the huge jackpot.
"I couldn't believe it the first time I checked the ticket! So I ran it through the machine again just in case there was a computer error," he told reporters. "I was standing up, but I had to sit down. I almost broke the chair, I was so flustered!"
If the ticket's owner isn't identified in the next two years, the millions will go to Gonzalez.
"For the first time we're looking for a millionaire, not because we want money from them, but because we want to give it to them," the mayor of La Coruña, Carlos Negreira, said on Monday.
Negreira said he'll buy Gonzalez a beer in two years if the good Samaritan gets to keep the fortune.
"He found something that wasn't his, and did the right thing to try to find who it belongs to," Negreira said. "He's a good example for our citizens who believe in justice."
Six people have already tried to claim the prize, NPR reported, but none of them were able to prove ownership: specific knowledge of when and where the ticket was purchased.