Fraudulent activity during the Christchurch rebuild should be acted on quickly rather than mopped up afterwards, departing Serious Fraud Office chief executive Adam Feeley says.
His comments come after Deloitte international corruption expert Peter Dent last week warned of the potential for huge amounts of fraud as the systems in place for the rebuild get stretched to the limit.
Mr Feeley said enforcement and regulatory agencies had made the mistake of mopping up after the fact at failed finance companies - but the office would not let that happen in Christchurch.
"It's incredibly important that we don't mop afterwards - we act now, we act in a very co-ordinated fashion, and we act in respect of what we know to be the problem,'' he told TV3's The Nation.
"The problem is at the moment, we're not sure what the problem is. But we every reason to believe - unless New Zealand is some unique anomaly in the world - that post-natural disaster you have fraud, and you have fraud on quite a big scale.''