According to local paper Le Nouvelliste, managers of the affected businesses were only made aware the banknotes were counterfeit when they took them to be deposited at the post office, where staff immediately picked up the fraud.
It's not the first time in recent months when fake 100 franc bills have turned up in the Valais. In late January the owner of the Big Ben Pub in Verbier identified several counterfeit notes in his takings, as did the organizers of two masked balls in Rarogne in late January, the paper reported.
A spokesman for Valais police told the paper such cases were rare and usually only happened when conditions were right.
“Such problems often happen when money is exchanged in darkness, or when there is noise and crowds. Carnival is therefore an opportune moment.”
However counterfeiting in the Valais is nothing new. Whether they are aware of it or not, today's money-forgers are mirroring the actions of a legendary predecessor.
Joseph-Samuel Farinet was an Italian counterfeiter who arrived in the Valais in 1869 and began minting fake 20 centime coins.
Wanted by the authorities, he stayed hidden by distributing his fake coins to local people in exchange for their help – as a result he garnered a reputation as a ‘Robin Hood of the Alps', since his money helped poor families.
He managed to evade police for years, but in 1880 was eventually tracked down and chased to a gorge above the village of Saillon, between Martigny and Sion, where he met his death in mysterious circumstances.
Farinet has since become a celebrated figure and has been mythologized in a novel and a film. His name is a common sight in the Valais – and the canton even named its new ‘local' currency after him last year.
It's unlikely today's forgers will be so celebrated...