New Zealand's biggest insurer has already logged more than 1200 claims from the weekend's floods and is warning about contaminated and dangerous properties.

Craig Olsen, chief executive of Insurance Australia Group (NZ), said most claims were made on Monday after the heavy rainstorm and flooding that hit northern parts of the North Island during the weekend.

"We have received in excess of 1200 flood claims so far. There was a spike in the numbers on Monday and we received more than 600 claims then. The majority are home insurance claims in Auckland," Olsen's office said.

IAG has the State, NZI, AMI and Lumley Insurance brands and Olsen said assessors were now busy working on the claims.


"The severe weather that hit upper North Island recently has been a real set-back to large number of our customers, and claims continue to be received.

"Assessors have been mobilised, but we would like to remind our customers to be aware of the potential issue of contaminated, or 'black' water, which can pose a health risk.

"It is a common issue during cleaning up after a flood event, therefore we have developed guidelines for anyone who has concerns or is experiencing this problem at the moment. Please take extra care while you are dealing with potentially contaminated items," Olsen said.

People should wash cooking, eating and other kitchen utensils that had been covered by the water, the insurer said. Flood water can also make air inside a house unhealthy.

"When things get wet for more than two days, they usually get mouldy. There may also be germs and bugs in your home after a flood. Mould may be more likely to make some people with asthma, allergies and other breathing problems sick."

The warning said people should not enter flooded premises before officials had said it was safe. Buildings could have hidden damage making them unsafe and people should look for electrical damage and beware if they see sparks or broken or frayed wires.

Vero said yesterday it had already received 200 claims worth about $700,000 but those were likely to rise.

AA Insurance said it had handled almost 560 flood-related claims during the weekend, mainly from people living in low-lying areas.


Read the full IAG warning here: