Queensland's opposition leader says whistleblowers won't take part in any state government integrity review out of fear of reprisals.
David Crisafulli's claim comes after Premier Annastacia Palaszczuk announced Professor Peter Coaldrake would lead a widescale probe into government accountability and workplace culture.
Two probes and three separate reviews have already been launched following weeks of misconduct allegations involving the government, the public service and the state's four integrity watchdogs.
The Liberal National Party leader said three whistleblowers including "one current senior public servant" had told him they had information on "issues that date back the last decade".
But he said they did not want to participate in an inquiry because they felt "the heavies could be put on them" if they spoke out.
"Whistleblowers have already contacted us to say that they would never speak in a review of this matter - they don't have the protection," Mr Crisafulli said on Sunday.
"Current public servants but also former ones who have moved to other roles and are concerned the heavies could be put on them for telling their story in an open forum.
"Only a royal commission will give people the protection they deserve to tell their story."
Mr Crisafulli also hoped Labor backbenchers who had spoken out off the record in recent NewsCorp reports on integrity issues would find their voice when state parliament resumes for 2022 this week.
"We need some of those brave souls this week in parliament," he said.
"This week is the most critical parliamentary sitting since the election of the Palaszczuk government over seven years ago."
Ms Palaszczuk on Friday announced Prof Coaldrake would lead the widescale inquiry despite the former Queensland University of Technology vice-chancellor making a donation to the Labor party in 2018.
Mr Crisafulli said Prof Coaldrake's appointment "doesn't pass the pub test".
"If for no other reason than perception," he said.
"Someone who has ... donated to the Labor party surely that is not the right person to pass judgement on corruption issues rotting the Labor party."
Transport Minister Mark Bailey said on Sunday Prof Coaldrake's reputation was "absolutely unquestioned".
