Christchurch police are investigating the theft of a significant amount of mail right across the city.
The Earthquake Commission (EQC) says 630 cheques it has sent out totalling $1.9 million have so far not been banked.
Detective Senior Sergeant David Harvey won't say how many letters have been stolen, but it is Christchurch-wide.
He says police have been investigating for two weeks.
New Zealand Post alerted police a couple of weeks ago, after it noticed several instances where mail had been stolen.
Mr Harvey says it's concerning that mail appears to have been taken from people's letter boxes, especially as many homes have been left vacant as a result of quake damage.
Householders advised to check boxes
With the extent of damage in Christchurch and the thousands of people displaced, EQC says some cheques could be sitting in uncleared mail boxes.
EQC says people who have moved need to let it know as soon as possible.
It also says it's possible some people who have received their cheques might not want to bank them as they are querying their assessment and believe by cashing the cheque they have accepted the commission's decision.
It is encouraging people to bank the cheques regardless, as they will still be able to continue to contest the assessment.
Earthquake Recovery Minister Gerry Brownlee has reiterated the need for people to make sure the commission has the right address.
In one example, he said, 32 houses in a street of 75 properties had incorrect addresses.
So far, the commission has paid out more than $1.1 billion in claims.