Christchurch police have laid charges against a householder they say submitted false invoices to the Earthquake Commission.
In a second case, police say a contractor is being investigated over invoices that appear to contain exaggerated figures.
Detective Senior Sergeant John Rae says the cases arise from complaints by EQC.
Mr Rae says a woman has been charged with obtaining an advantage by false pretences which carries a maximum penalty of seven years' jail.
It is alleged the woman faked invoices, indicating that she had paid them before seeking reimbursement from EQC.
The second case involving a contractor is still being investigated.
Mr Rae says the cases are the first of their kind relating to the Canterbury earthquakes, but expects more will follow.