Ms Trad is in a legal fight to stop the Crime and Corruption Commission from releasing its report into allegations she interfered in the recruitment of under-treasurer Frankie Carroll in 2019.

The CCC has revealed its own legal costs, and outlined nepotism allegations regarding public service appointments, in a letter to a parliamentary committee.

Liberal National Party MPs tried to release a redacted version of the CCC's letter during a committee meeting on Tuesday.

However, Labor MPs Jonty Bush, Jess Pugh, Corrine McMillan and Ali King vetoed the LNP motion.

The trio argued the letter couldn't be released, even redacted, as Ms Trad's matter involving the CCC was still before the Supreme Court.

After the hearing, Ms King and Ms McMillan refused to speak to waiting journalists about why they blocked the release of the CCC letter.

LNP Deputy Leader Jarrod Bleijie accused the government of "running a protection racket" for their former Labor colleague.

"I cannot see any reason why the Labor Party would want to hide the legal costs of the CCC incurred into the Jackie Trad legal matter," Mr Bleijie said in a statement.

"I would encourage the Labor party members not to try and continue the protection racket on Jackie Trad ... I would ask them to put what's in the public interest and that is releasing the letter."

Mr Bleijie said the CCC's probe into Ms Trad had been completed, and there was no apparent legal reason to suppress the CCC's legal costs.

"Revealing that the legal cost to the taxpayer that the CCC has spent in court does nothing to impact the case before the court," he said.

Australian Associated Press