The boss of New Zealand's biggest bank has pushed back against questions over its sky-high profits

Parliament's finance and expenditure committee is holding an inquiry into banking competition.

ANZ chair Scott St John has been the first to get grilled - and defended the bank's two-billion-dollar profit.

He says they aspire to be a high performing bank that supports the economy, not to be average.

Meanwhile -- ANZ chief executive Antonia Watson denies there are a lack of strong players in the market.

She says the market is not without competition, and staff are going out every day to win customers.