The Government has received a nearly three-fold increase in its dividend from the Reserve Bank in the past year.
The bank's profit nearly doubled to $906 million in the year to June, compared to $535 million in the previous year.
The bank's annual report shows the biggest contributor to the profit was a $481 million dollar gain from the sale of foreign currency.
The bank's foreign reserves ballooned two years ago after it intervened in currency markets to try to bring down the value of the New Zealand dollar, which was above 76 US cents at the time.
That attempt failed, but has since yielded huge profits for the bank.
The bank received more New Zealand dollars than it paid out to buy foreign currency as the Kiwi fell in the wake of the global financial crisis.
Of its profit, the bank pays a $630 million dividend to the Government.
The Labour-led government changed the rules last year, so the Crown gets paid two-thirds of the bank's profits, up from one third previously.
