A complaint against a campaign urging people not to give money directly to beggars has been upheld by the Advertising Standards Authority (ASA).
It relates to a poster produced by Nottingham City Council which states "90% of the money given to beggars goes straight to drug dealers".
Council officials say the figure is based on fact while the ASA says it is based on estimates.
The campaign could be reused if there is enough evidence to back it up.
Carol Forbes from the authority said: "Whatever claims they make in their advertising have to be backed up by conclusive evidence.
"As we've seen with this particular case there is lots of different research, a lot of different reports about what beggars spend their money on and we felt they hadn't conclusively backed up this particular claim.
"But there is obviously no reason why if they have got evidence to back up the claims that they cannot advertise in the future."