Parliament's Registrar of Pecuniary Interests is recommending changes to tighten the rules requiring MPs to disclose their financial interests.
Dame Margaret Bazley has told MPs the current standing orders do not always provide certainty about what they have to declare.
Parliament's Standing Orders committee is reviewing the rules covering the disclosure of pecuniary interests.
It follows several MPs having to amend their records in recent years, including Attorney-General Chris Finlayson and Te Atatu MP Chris Carter.
In her submission to the committee, Dame Margaret recommends changes designed to ensure MPs declare all trusts they are aware of, or ought to be aware of, that they are a beneficiary of.
She also recommends the establishment of a catch-all category to allow MPs to declare any interests not covered by the current rules.
Dame Margaret is calling for stricter rules on the disclosure of company directorships, even if a company is no longer trading.