Sense, the deaf-blind charity, said hundreds of its sacks had been copied and left at homes across Canterbury.

Ann Young, who organises legitimate collections in the area, said they were then being picked up by "rogues" who were stealing their contents.

She added that it was probably costing the charity hundreds of pounds.

The bogus collections are being investigated by Kent Trading Standards.

Spokeswoman Marion Ward said: "It does seem particularly unkind when charity shops are relying on the goodwill of the public.