Parliament's powerful privileges committee has found Christian Porter did not break any rules in not declaring a blind trust, but has recommended the rules be updated.
The committee concluded it was up to individual members about how much information is disclosed on the register.
But the committee also found the rules should be updated in order to uphold the integrity of the member's register of interests and provide the highest level of transparency with regards to gifts and donations.
The report says the register should have more details on requirements to help MPs meet the standards expected from parliament.
Mr Porter sued the ABC for defamation over an article airing allegations of a 1988 rape of a now-deceased woman by a senior cabinet minister.
He vehemently denied the allegations.
Mr Porter ended up resigning as a minister after his legal bills were paid for by a blind trust but remained adamant he had not broken any rules or breached ministerial standards.
Prime Minister Scott Morrison said he was unable to conclusively rule out any perceived conflict of interest despite Mr Porter's assurances no banned donors contributed to the trust.
Then-Speaker Tony Smith ruled there was a prima facie case to refer the donation matter to the privileges committee to determine if he acted in contempt of parliament.
The government voted down a Labor referral motion, angering the opposition who said it was unprecedented the government had ignored the speaker's finding.
On Tuesday, committee chair Russell Broadbent told parliament he would resign in the first sitting week next year after the committee's findings were leaked to a media organisation prior to the report being presented.
Mr Broadbent said it was clear the article published by the Guardian on Monday night was the result of someone leaking private deliberations of the committee.
Unauthorised disclosure of committee findings is prohibited and Mr Broadbent said the matter would be investigated.
"The walls of the integrity, intention and spirit of the committee have been breached," he said.
Opposition and government MPs urged Mr Broadbent to reconsider his decision, telling him he still had the confidence of the committee to remain chair.
Australian Associated Press
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