The estimated size of earthquake claims against failed New Zealand insurer Western Pacific has increased as assessments are finalised.

A previously predicted $NZ49 million ($43.78 million) in claims from the September 2010 and February 2011 quakes grew to $NZ58.7 million ($52.45 million) at September 30.

Liquidators David Ruscoe and Richard Simpson of Grant Thornton say this is “highly unusual” but they expect the figure to increase as assessments are completed.

Mr Ruscoe told insuranceNEWS.com.au the original sum was derived from initial assessments and company records in 2011, but a claim for substantial damage has risen after a structural engineer inspected the affected property.

The liquidators also say they have completed their investigation into the company’s affairs and do not believe it will serve creditors’ interests to pursue legal action against the directors – Melbourne-based Jeff McNally and his brother-in-law property investor Graham Smolenski.

The small insurer collapsed in 2011, and its only significant asset to compensate Canterbury quake claimants is $NZ32.19 million ($28.76 million) in reinsurance.

The liquidators say preferential creditors – the Inland Revenue and employees – are likely to get a distribution in the next year, but that will depend on recovering outstanding debts, including unremitted premiums held by brokers.

“Claims have been served on the relevant brokers and we will be continuing with the court process in the coming months,” the eighth creditors’ report says.

The liquidation will continue until at least 2016 as the Canterbury claims are processed.

Unsecured creditors, including those with non-earthquake insurance claims of $NZ15.41 million ($13.77 million), are likely to get nothing.