Bascand said until it was satisfied that Westpac's remediation work was complete and effective it was increasing the bank's required holding of liquid assets.
The bank regulator can require the reports under section 95 of the Reserve Bank of New Zealand Act 1989.
In a statement Westpac New Zealand said it acknowledged the importance of liquidity and risk governance obligations and would support the independent reviewers to provide the necessary reports to the Reserve Bank.
"WNZL will also act promptly on any recommendations from the reviews.
"WNZL has taken a number of steps to improve risk governance but recognises more work is required, and supports the additional oversight that the independent reports will provide."
The bank said the reviews only applied to WNZL and not the governance processes of Westpac Banking Corporation in Australia or its New Zealand branch.
The Reserve Bank noted that it was confident that Westpac New Zealand's current liquidity and funding positions were sound and that the bank was well capitalised.