In its major report into competition in the banking sector, the Commerce Commission found that KiwiBank was the only player that could be a `maverick disruptor' to the Australian banks.
But KiwiBank lacks the scale and capital to consistently drive competition, and the government as owner should consider ways to provide that capital, the Commission said.
The Finance Minister said last month she wants KiwiBank to grow to become that competitive disruptor.
Nicola Willis said the government is open to outside investment, and has cited the likes of Kiwisaver funds as sources to top up the bank.
The minister expects to take options to Cabinet by the end of the year.
KiwiBank's chief executive says he's not opposed to some overseas investment coming in for the bank.
Steve Jurkovich says the bank, which at the end of June had a market share of 7.6 per cent, could double that with a capital injection.