The explosive allegation was made in a letter from Queensland's Whistleblower Action Group to Attorney General Yvette D'Ath on February 14, 2016.

Queensland Whistleblower Action Group president Greg McMahon will raise the "issue of trust" allegation when he speaks on Thursday at a two-day forum hosted by the Crime and Corruption Commission on a discussion paper on whether media can report the watchdog is investigating allegations of corruption.

Mr McMahon said the serious issue goes to "whole tone of trust" between whistleblowers and the Crime and Corruption Commission.

The Crime and Corruption Commission told key Heiner Inquiry whistleblower Kevin Lindeberg in a letter on March 2, 2015 it would appoint "an independent person, external to Queensland" to investigate why it took 26 years to find there was a prima facie case against politicians who shredded Heiner Inquiry documents wanted in court.

The CCC instead appointed a retired Queensland Supreme Court judge - without telling Mr Lindeberg – to complete the investigation instead.

Fairfax Media is not saying the review is inadequate.

The Crime and Corruption Commission on Wednesday declined to comment on the allegation and would not answer questions on the issue.

The Parliamentary Crime and Corruption Commission – the parliamentary body that oversees the Crime and Corruption Commission – has been investigating this allegation since May 2016.

A stunned and horrified Mr Lindeberg – who provided previously confidential information to the CCC – reported the "switch" to Queensland Whistleblowers Action Group, which subsequently wrote to Attorney-General Yvette D'Ath in February 2016.

Mr Lindeberg has, until this week, declined to comment, concentrating on a remembrance for aviation hero Bert Hinkler.

"I wasn't just promised an interstate judge by the CCC's mere whim or chance," Mr Lindeberg said.

"It was because the law and ethics required such an appointment in this Heiner affair context, " he said.

"This is all about trust in public office. Without trust we are all left with absolutely nothing. We will be left to the fate of the roulette wheel of anything goes, particularly self-interest by and for those in power."

Mr McMahon said he believed the switch by the Crime and Corruption Commission was a real-life "test case" for media and the Crime and Corruption Commission.

"We are concerned when an undertaking is given to a whistleblower that they will conduct an investigation in a particular way – and then without telling the whistleblower – they renege on that undertaking," Mr McMahon told Fairfax Media.

Mr McMahon said Queensland Whistleblowers agreed with Mr Lindeberg that the issue of why the Heiner Inquiry "cover-up" was investigated by a Queensland judge – which Mr Lindeberg has always opposed – must be investigated.

Mr Lindeberg has always insisted interstate judges should investigate why it took 26 years to find there was a "prima facie" case against Goss Government MPs who voted to shred the Heiner Inquiry documents in 1991.

"He is asking for the set of circumstances - where he was given an undertaking - where the undertaking was reneged without telling him," Mr McMahon said.

"He wants to have that investigated, and we support that."

Mr McMahon said Mr Lindeberg's allegation must be investigated.

"It is a test case of how they may behave – if what Mr Lindeberg is saying is true – if they had this rule.

"The matter needs to be investigated, because Mr Lindeberg has documents tending to show that the allegations may be true."

Attorney-General Yvette D'Ath has written back to Queensland Whistleblowers saying she does not intend to allow the bill (Cunningham Bill) – presented by former PCCC chair Liz Cunningham in November 2014 to allow interstate judges to investigate these issues - to be represented.

Mr Lindeberg said he believed the issue showed why media should not be hamstrung.

"The crisis is real, serious and now," he said.

"At the very time when the authorities may make it a crime for a whistleblower like me to make allegations like this public to the media, this scandal demonstrates why we always need a fearless and free media more than ever to tell us the truth instead of being kept in the dark by those in power."

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