Police are warning members of the public to be vigilant, after a number of charity fraud cases in county.
Officers are now investigating a number of reports of individuals knocking on doors allegedly canvassing for money for the Child Brain Injury Trust.
A spokesman for Cambridgeshire Police said: “The calls that we have received have raised concerns that strange questions were being asked.
“We have been in contact with this organisation this morning. It is based in Oxfordshire, and does not carry out door to door requests for charitable donations.
“Fraudsters use the name of genuine and often well known charities to obtain money. We advise residents not to buy at the door. If you wish to give to charity, please ensure that you are able to make an informed choice, in your own time and be absolutely certain that you are giving to a genuine cause.”
To read more Action Fraud advice on this subject visit: : http://ow.ly/sivr30mIX9l