The wind farm on Shetland has been the target of protests
Wind farm developers in Shetland have been told to scrap an advert with misleading financial and environmental statements.
The Advertising Standards Authority has upheld four complaints against the leaflet, which was published in May.
Campaigners against the wind farm said the decision cast doubt over the benefits claimed by the developer.
Viking Energy admitted its wording was "clumsy" but denied any suggestion it was trying to mislead.
The project, for 150 turbines, is a joint venture between Scottish and Southern Energy and the island community.
The ASA said claims that 50% of the profits would stay in the Shetland Community were wrong since 5% included in that figure would go to four local shareholders.
It also said claims that up to £30m could go into the Shetland economy each year and £18m could be earned by the public purse, were not sufficiently flagged up as mere estimates.
The ASA also said claims made in the leaflet that the amount of atmospheric pollution caused during construction could be balanced out by fewer than three years of wind farm operation, were unsubstantiated.
Vice chairman of the opposition group Sustainable Shetland, Kevin Learmonth, said the ruling "puts a big question mark over Viking Energy's key financial and environmental claims".
Viking Energy's project co-ordinator Allan Wishart said the company stood by its figures as being the best available estimates, but admitted the way they were presented was "clumsy".
He said the company apologised if anyone was misled.
Meanwhile, an anti-wind farm group was told it must substantiate future claims after the advertising watchdog upheld a series of complaints about a campaign leaflet.
Save Our Scenic Moray (SoSM) published a circular setting out its opposition to the proposed Dorenell wind farm, near Dufftown in Moray.
The leaflet was reported to the ASA by Pendragon Consultants, acting on behalf of renewable energy company Infinergy.
It challenged whether SoSM could substantiate its claims that the wind farm was a threat to Whisky Glens, that rare golden eagles would die in turbines and that the plan presented "a danger of wildlife disturbance, pollution of rivers and loss of habitat".
It also asked if the group could substantiate its claims that a wind farm would deter visitors from returning to the area and accommodation providers would suffer "a cash loss".
The ASA told the group the circular must not appear again in its current form and it must ensure it held "robust evidence" to support future claims.