The Advertising Standards Authority (ASA) has upheld a complaint over claims being made by campaigners opposed to a large wind farm development.
Campaigners are opposed to the wind farm
The Ochils Environmental Protection Group is fighting plans for a farm near Dunning in Perth and Kinross.
It produced a leaflet and fact sheet which predicted that there would be a large fall in house prices.
It also claimed that wind farms caused illness - but the allegations were dismissed as misleading by the ASA.
The authority was responding to a complaint from a member of the public.
The unnamed complainer challenged a claim that wind farms create inaudible sound frequencies which cause stress-related illness.
The group's leaflet also said that house prices fall by up to a third where the outlook or amenity is affected by a wind farm.
These claims were dismissed by the ASA, along with others about the impact on wildlife.
Protesters' spokeswoman Ginny Stacy-Marks said: "I'm rather cross about it but it's not going to make me, or any of the people living in our community in the Ochils give up our fight.
"I would actually dispute the fact that what was contained in the leaflets was incorrect."
She added: "The so-called judgement against us does not hold water. Had we been a political group they would not have been able to touch us."
Campaigners vowed to continue the fight against the Dunning development and a number of other wind farms proposed in the area.