Christchurch police are warning residents that just because someone is wearing a high visibility vest does not mean they can trust them.
Police say they have had several cases of people pretending to be officials carrying out earthquake-related work when they are actually looking for houses to rob or trying to scam people.
Inspector Paul Fremaux says he has heard reports of a pair of men claiming they were going door to door carrying out rapid assessments, when in fact assessments had already finished.
Mr Fremaux says he has also heard of a woman posing as a Work and Income employee demanding bank account details, and threatening to cut off a resident's benefit if they did not give them.
He says residents should always ask such people for identification and notify police if they have any concerns.