An elderly Sheffield couple had cash stolen from their house as men offered to clean their guttering.
The man and woman, aged in their 80s, opened their door to three men who offered to clean out their guttering for £20.
But when the trio left the property in Revill Lane, Woodhouse, it was discovered that cash inside had been stolen.
The men, two of whom were white and one mixed race, struck yesterday afternoon.
They left the scene in a white van.
Inspector Jason Booth, of South Yorkshire Police, said: "People need to be careful when answering their doors to cold callers offering to complete work for cash.
"In doing so the work may not be to a good standard and customers may have no redress if anything goes wrong.
"There is also the risk of being charged more than agreed."
Anyone with information should call South Yorkshire Police on 101, quoting the crime number K/86199/2017.