Jersey Police have spoken to the rogue traders offering extortionate prices to clean patios and driveways.
The group of men were going door to door with flyers offering work without a valid working permit.
Islanders who've paid money for their services have been refunded.
Inspector Andy Bisson urges people to be careful if this happens again in the future.
"They've basically been told that without a licence, they commit an offence and they will be dealt with. Enquires are ongoing with them, us and the licencing authority.
"We have had it (rogue traders) in the past, not with the same group, but every now and then you get people coming over that see it as an opportunity and an easy target for money.
"Don't go straight away by one flier. Make a couple of enquiries, speak to people who you trust and rely on and then discuss it before you make that decision."
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