Mr Hill said if sign owners failed to comply with the rules they would be sent a follow-up letter.
"If they still do not comply an abatement notice would be issued and if they did not comply with that, they could receive an infringement of $750 for failing to comply with an abatement notice. The next step after that could be legal action."
Mr Hill said staff would be checking the signs again next week. "The legal advice is privileged information but we can confirm the signs do not comply with the District Plan rules. Of the 10 sites identified, all owners have been advised and some have not taken their signs down."
Rotorua District Residents and Ratepayers group chairwoman and district councillor Glenys Searancke said the group did not consider the signs as temporary as the message on them changed regularly.
"We will have to wait and see what happens," she said.
"We have lots of people keen to have the signs on their property. This all seems like snakes and ladders."
Mrs Searancke said she would speak to the group's committee about getting its own legal advice on the matter.
"There are far more serious matters to deal with than signs. Some people really like them," she said.