A 78-year-old widow had donated the box of left-over high-calorie drinks to the Lindenhof Senior Centre in Lürrip after the death of her husband, the Rheinische Post (RP) reported on Friday.
But, as residential manager Anja Maser unpacked the drinks, she came across a heavy ice-box hidden underneath, full of shining, gold coins.
Maser immediately brought the box to her colleague, Claudia Spetsman who recognised that each coin was marked with the South African national animal, the Springbock.
Spetsman researched the coins on the internet, identifying some of the coins as South African Krugerrands which hold a tremendous value.
The box contained 109 coins in total, which wouldn't seem like a fortune if it weren't for the fact that each one-ounce gold Krugerrand is worth around €1,000.
What's more the box contained a number of older and even more valuable coins, bringing the total value to over €100,000, reports Express.
After realising the worth of their findings, the carers contacted the police and the search began for the mysterious donor.
"We knew absolutely nothing about her as the senior centre only moved to Lürrip a few days ago," Spetsman told the RP.
Luckily the police found an address sticker on one of the boxes - it seemed the specialised nutritional drinks were previously delivered by post to the widow's husband.
When the police returned the coins to the widow she was flabbergasted. According to the RP, she had known about the collection of coins but had no idea how they had ended up in the donation box.
The 78-year-old was hugely grateful to Maser and Spetsman for handing the fortune in to the authorities. "The behaviour of the women is super," she told the RP.
The police are now investigating how the coins got into the box, Focus reports. According to the police, the woman suspects it was some kind of con or plot to steal the valuable collection.