Cologne officials said the locker at the city's main train station was opened when its lease expired in April and officials discovered it contained several pounds of gold and a large amount of cash, The Local.de reported Monday.
Cologne Chief Prosecutor Ulrich Bremer said police are keeping specific details about the find under wraps so the owner will have a way to prove ownership.
"We kept it short so as not to give claimants too much information," Bremer said.
He said the owner will have to know "the exact sum of money, how many gold bars there were, and what sort of imprints the bars had on them."
The gold will be auctioned off and the proceeds will be used for public funds if the owner is not identified, officials said.
"It's possible that the items are the product of a crime, and that's why no one has come forward, but we will have to wait and see," Bremer said.