"She told me the police had been called."
Wanganui Police Sergeant Kevin Smith said there had been reports of a middle-aged man approaching people offering similar services before.
He said it was not a normal way to do business, and people should be sceptical.
"I'd be very cautious and verify the nature of that business."
Mr Smith could not confirm how they had dealt with the man.
Neighbourhood Watch co-ordinator Jean Toki said the man had been going between houses in Stafford St offering to clean gutters and windows and she had phoned the police.
She had been previously warned the man was in the area and had passed that information to residents and called the police when he was in the area.
"We've got to be so alert today," she said.