Calls for a banking inquiry are being strengthened by mounting issues around our largest bank

ANZ New Zealand CEO David Hisco is stepping down over concerns he may have charged tens of thousands of dollars of chauffeuring and wine storage to the company card.

JMI Wealth's Andrew Kelleher says it comes just a month after the Reserve Bank censured ANZ for "persistent failures" in calculating risk capital.

He says it's terrible timing for the company's chair Sir John Key ... and there will be calls for inquires into the sector.