An upmarket Auckland house sold to David Hisco's wife by former employer ANZ Bank for $6.9m was worth $11 million, according to an independent valuation released by KiwiSaver provider Simplicity.

The Hiscos' St Heliers house, purchased by ANZ subsidiary Arawata Holdings in 2011 for $7.5m, was subsequently sold in 2017 for $6.9m to Hisco's wife Deborah Walsh.

ANZ announced in June that Hisco would depart following an investigation which alleged he "mis-characterised" certain personal expenses as business expenses.

The house sale emerged as ANZ deflected questions about the bank's culture and conduct.

Simplicity commissioned the independent valuation after the refusal by ANZ to release valuations used to validate the sale price of $6.9m.

"The house was bought and sold by the ANZ using shareholder funds, which includes the money of many KiwiSaver members" Simplicity chief executive Sam Stubbs said in a statement.

"It was sold for a price well below it's value at the time, as assessed by QV, and now an independent valuer. Given the sale was between related parties and was not disclosed
as it should have been, it is very suspicious and needs to be justified to shareholders," Stubbs said.

"The ANZ is our largest bank, and most profitable company. It needs to be held to the highest standards of disclosure and transparency," he said.

"Not disclosing the sale of the house to shareholders, and refusing to disclose the valuations it claims it has, is far from meeting those standards," he said.

At the time of sale the house had QV value of $10.75m.

The current ANZ New Zealand chief executive, Antonia Watson, was a signatory to the sale.

ANZ said in a statement:

"The house was sold by ANZ to Mr Hisco's wife based on independent valuations."

"We have voluntarily provided relevant information, including those independent valuations, to the FMA and RBNZ. We'll continue engaging with the regulators on the issue."