Northampton Borough Council has issued a warning after a resident in Lower Thrift Street was sent a false letter claiming to be from the authority.
The letter, which bears the council logo, has not been sent by the council.
The letter informs people that Environmental Health Officers will be visiting properties within the coming fortnight to install mandatory radon gas monitoring devices in their homes.
Council officials have warned that the letter is a fake and are warning people to contact the council if they received one. It is believed the letters have been posted in the NN1 area of the town, but it is not known if they have been more widely distributed.
Northampton Borough Council does not undertake radon testing, and would not undertake any work without a pre-arranged appointment.
Should you receive a letter please contact Northampton Borough Council Community Safety Team on 01604 837752.