The unofficial posters urged citizens to report their neighbours if they overheat their homes this coming winter.
Swiss police are investigating a fake advertising campaign that encouraged people to report their neighbours.
Citizens were told to notify the authorities if anyone heated their homes more than 19 degrees Celsius this winter amid the energy crisis. A reward of 200 Swiss francs (€208) was supposedly offered for the anonymous tips.
The fake ads were widely shared on Telegram and other social networks and also appeared in public at a bus stop shelter.
The misleading campaign was also reported by state news organisations in Russia and Belarus, while some social media users falsely suggested that citizens could even be imprisoned for heating their homes too much.
Online images showed a young woman using a mobile phone and the tagline: "Does your neighbour have their heating set at more than 19C? Please contact us."
The recognisable logo of the Swiss Confederation’s coat of arms also appeared on the ad poster.
The Department of Environment, Transport, Energy and Communication (UVEK) has described the ad campaign as a "manipulation" and warned citizens against the "false" message.
"The federal government has nothing to do with this call and formally distances itself from it," UVEK said in a statement.
"There are neither such posters of the federal government nor corresponding requests, it is obviously a manipulation."
Open Source tools show that the stock image of the woman has been used online since 2021.
The Swiss government has launched a campaign encouraging homeowners not to waste energy amid rising gas and oil prices amid Russia's invasion of Ukraine.
But instead of reporting on their neighbours, citizens have been urged to take other measures such as lowering their thermostats, covering pots and pans while cooking, and turning off lights and appliances when not in use.
Swiss federal police said on Thursday that they had received a complaint for “abusive use” of the coat of arms and other possible misdemeanours. An investigation is ongoing.