The Serious Fraud Office has launched its first investigation into alleged earthquake insurance fraud in Christchurch, which could involve tens of millions of dollars.
Chief executive Adam Feeley will not name the insurance company that made the complaint.
Nor will he say whether staff are involved or if someone outside the company has been organising multiple false claims.
But he says there are things to look out for in detecting such crimes.
"Someone taking a lot of responsibility and indeed excluding others from knowledge about transactions going on, for example someone saying: 'I will deal with all these claims, no-one else needs to see them, I've got them covered.'
"If that's not your normal process, then you've got to ask yourself why is someone not sharing that information."
Mr Feeley says there are two types of crime that are likely to happen in Christchurch.
"One will be big one-off frauds; the other will be low-value, high-volume frauds which collectively add up to a lot, and the case we're looking at may be an example of the latter, where it may be that there has been systematic defrauding of an insurance company."
Mr Feeley says the investigation is still in the early stages.