Queensland MPs declare cars and theatre tickets, but a large taxpayer-funded payout to the head of parliament’s anti-corruption group is a grey area.

Disclosure rules need to be changed after the head of Queensland parliament’s anti-corruption committee was compromised because a $769,000 payout was not publicly listed, the Palmer United Party (PUP) says.

Steve Davies, chairman of the crime and misconduct committee, was compensated by the government two years ago because a new busway affected a Bank of Queensland franchise he ran with his brother.

The Liberal National Party backbencher and his brother Brett successfully sued the Department of Transport and Main Roads in 2012, arguing the busway compromised customer parking at their Coorparoo business.

The Land Court decided in their favour and awarded them damages, accounting for them moving to nearby premises in 2009.

Mr Davies did everything right by declaring the court case and the compensation payment to the clerk of parliament at the time, and provided a statement.

But the payout is not listed on the public register of MPs’ interests because it is considered part of a business.

“Everything the clerk asked me to do I did in spades, plus some,” Mr Davies told AAP.

“I went above the call of duty.”

The PUP’s Queensland leader, Alex Douglas, who previously headed parliament’s ethics committee, said it was a grey area and did not suggest any wrongdoing by Mr Davies.

But he said the process of declarations needed changing.

“If there’s some matter that’s outstanding, it must be declared,” Dr Douglas told reporters.

“It makes it very difficult for anyone to have any faith that that position has not already been compromised.”

MPs are spared from declaring income from a business, even though they are required to state their business interests and directorships.

The Davies brothers bought their bank branch for $480,800 in July 2005. Steve Davies is a 50 per cent silent partner as an MP.

MPs are required to declare loans, assets worth more than $5000 and gifts valued at more than $500.