The Office of Fair Trading is warning the public about tradesmen offering to do tarmacking.
The department has received reports of the workers visiting and cold calling residents - which is illegal in the Isle of Man.
They claim they work for a local company and are using leftover materials from previous jobs.
They were last spotted in an English-registered wagon in the South of the Island yesterday.
Stop putting knives in recycling, says council
Bee Gees to release limited-edition box set
Northern Irish politician criticises Manx visa rules
Elective surgical unit opens at hospital
Piling rig on TT course tonight
10-day bus strike from next weekend
Yellow snow warning issued by forecasters
Ramsey harbour keeper completes 3,000-Mile Atlantic crossing