In evidence to a parliamentary committee, Auditor-General Grant Hehir said the requests had been made in the health and defence portfolios, and he had agreed to adjust material in the reports as it didn't affect his overall findings.

Under a section of the Auditor-General Act, the Attorney-General can direct information to be suppressed in a report if it is deemed to be contrary to the public interest, a power that was used controversially three years ago to suppress a finding that billions of dollars spent on military vehicles wasn't value for money.

In a separate decision released on Wednesday, the government will be forced to hand over the unredacted version of that three-year-old report, after independent senator Rex Patrick won his case in the Administrative Appeals Tribunal against the Department of Prime Minister and Cabinet to have it released under freedom-of-information laws.

The full report, which investigated whether Defence had got value for money in the procurement of a fleet of Hawkei light protected vehicles from Thales, was subject to a long-running saga, where Attorney-General Christian Porter agreed to a request from the weapons manufacturer to use the section of the Auditor-General Act to black out part of the findings.

Thales took umbrage with six paragraphs, now known to say the government could have got similar vehicles for half the price if it had bought an American-manufactured version, instead of going with a local build.

The unprecedented use of the powers to suppress the information brought to light questions over whether the independence of the Auditor-General was properly protected, questions that continued on Wednesday when Mr Hehir told the committee about the further requests.

Mr Hehir told the committee he was reluctant to use section 37 of the act as it "effectively gagged the office from ever talking about the issue".

"I could be sitting here, and the department may say something which isn't quite consistent with the evidence that we've got, and I can't say a word about that," he said.

"I regularly exclude information and don't put it in, but to formally do so under the act is just such a significant impact on our ability to support the Parliament that I don't think it's that effective at the moment."

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Until the Thales case, Mr Hehir said section 37 of the act had never been brought up by agencies being audited, but it had been done a handful of times since.

He has previously labelled the saga the most significant issue in his time in the job.

Tribunal deputy president Peter Britten-Jones, who heard the case brought by Senator Patrick, said the Thales representative's "contention that disclosure of the Disputed Material would be damaging is simply his opinion and, with respect, is self-serving".

"It is not the type of evidence which would be required to sustain a claim for exemption," he said.

Senator Patrick, who represented himself in the case against the Australian Government Solicitor, said it was a significant decision.

"Back in in 2018 the Attorney-General sought to censor an Auditor-General report that was to be tabled in Parliament. It was an extraordinary use of a little-used power," he said.

"What the AAT decision shows is the Attorney-General exercised extremely poor legal and political judgment in relation to the audit report."

Senator Patrick said it raises deep concerns about other legal decisions, including the move to prosecution in terms of whistleblowers Witness K, Bernard Collaery, David McBride and Richard Boyle.