More than 1,000 stickers were put on gravestones and wooden crosses at three cemeteries in the southern German city of Munich.
The stickers, which have been put on both old and recent graves, have a QR code that when scanned shows the name of the person buried and the location of their grave in the cemetery.
The 5x3.5-centimeter (1.95x1.2-inch) stickers surfaced in recent days at the Waldfriedhof, Sendlinger Friedhof and Friedhof Solln cemeteries.
Police are investigating the incident.
Read more from Sky News:
Starmer backs Zelenskyy after Trump 'dictator' jibe
Money blog: Chef reveals the one thing you should never buy
"We haven't found any pattern behind this yet. The stickers were put both on decades-old gravestones and very new graves that so far only have a wooden cross," police spokesperson Christian Drexler said.
"People who have witnessed anybody putting the stickers on the graves are asked to reach out to the respective cemetery's administration," Mr Drexler said.
(c) Sky News 2025: Mysterious QR code stickers appear on more than 1,000 graves in Munich
Female prankster pretending to be marshal sends Glasgow runners on 2.5km detour during race
Large sinkhole forces closure of Godstone High Street in Surrey
Snow village in China apologises for using fake snow during unusually warm weather
Ice hockey game between USA and Canada has three fights in first nine seconds
On Air