The picture emerged after a woman in Stockholm noticed that a receipt from a Coop store in the Swedish capital had some unusual text on it:
In capital letters, the receipt read: "DON'T COME BACK! SIEG HEIL".
Sieg Heil is a German Nazi greeting meaning "Hail victory" and was made infamous during World War II.
The woman, named only as Kerstin by the Aftonbladet newspaper, said she got a knot in her stomach when she read the text.
"I can confirm that this happened. It's completely unacceptable and we're very disappointed," Louise Stephan, Coop's press manager told The Local.
She denied that someone had hacked into the system, explaining that the message was manually added to the system by an employee.
"We've launched an investigation to see what consequences this will have."
She refused to comment on whether the person behind the text had been identified, or whether they would be fired.
Stephan added that the "Nazi receipts" had only been found at the one Stockholm store, and that only two were printed out.
The story on Aftonbladet, Sweden's biggest newspaper, shot to top of the most-read section and has been shared 14,000 times on Facebook.
The news comes just days after the nationalist Sweden Democrats, led by Jimmie Åkesson, doubled their support in the national election, grabbing 12.9 percent of the Swedish votes to become the country's third largest political party.
The Sweden Democrats have Nazi roots but its members have sought to distance themselves from their past in recent years.
However during the election campaign a local candidate quit the party after photos emerged of her wearing a swastika armband.
A similar receipt scandal cropped up in Italy recently, when a restaurant bill included an anti-gay message from a waiter reading: "I warn you, they're faggots".