The taxpayer-funded trip came three months after a ban on spouse travel, but Lyle Dunne's travel to Samoa with his wife was approved by Assembly Clerk Tom Duncan before the April ban.

Of the $9000 cost, $4900 was for Mrs Dunne and $4100 for her husband. She was attending the Presiding Officers and Clerks Conference, where she delivered a paper entitled "Parliamentary integrity: an oxymoron?".

It was the final trip taken by a politician's spouse after the Remuneration Tribunal decided the travel was not justified and the money better spent elsewhere.

The tribunal brought forward the ban and a decision to scrap study tours after hearing of a planned trip by Mrs Dunne, her husband, and fellow Liberal Giulia Jones and her staffer to study prostitution laws in Europe. The trip, costing $37,000, went ahead in May, despite strong advice from the clerk that taxpayers should not fund the trip for Mrs Jones' staffer. While spouse travel was within the rules when that trip was approved, staff travel was "a new frontier", Mr Duncan advised.

When it banned the spouse travel and study tours in April, the tribunal said no new travel requests could be made, but travel already approved could be taken.

Liberal leader Jeremy Hanson said on Monday the annual meeting of speakers had been attended by previous speakers from all parties, The travel to Samoa had been approved by the clerk and Mrs Dunne's decision to take her husband was "consistent with other attendees of the meeting and was appropriate".