Fake phone calls have been made to households by people claiming to be from Essex County Council.
The authority has warned people to be on guard after receiving a handful of queries from anxious residents.
In one case, a resident said they were called by someone asking to speak to a relative who had died a few years ago.
John Jowers, cabinet member for communities, said: “There will be times when we do need to ring residents at home but normally this would not be a surprise to the person concerned.
“So if you do receive an unexpected call from someone claiming to be from the council and you do not feel it is genuine please don't provide any personal information.”
If a suspicious call is received, Essex County Council advises residents to take the person's name, department and telephone number and then call its contact centre on 0845 743 0430 and ask if the person can be verified.