After MPs launched an inquiry into Attorney-General Christian Porter's order that parts of the audit report be blacked out, the Centre Alliance senator wants another probe focusing on allegations the company breached rules protecting the work of parliament.

Senator Patrick alleges Thales acted unlawfully in its attempt to stop the report's release during legal action in the Federal Court when the company tendered documents covered by protections letting parliament conduct inquiries unhindered.

Thales has denied the allegation and said it was not acting in contempt of parliament when it tried to stop the national audit office from publishing findings about the federal government's deal with the company to purchase new light protected vehicles for the army.

Senator Patrick on Wednesday night told the parliament its privileges committee, looking at conduct obstructing the work of parliament, should exert its power by investigating Thales Australia and suggested it could make an "appropriate ruling" against its chief executive, Chris Jenkins.

The senator said Thales in early 2018 unlawfully tendered to the Federal Court sections of the draft copy of the national auditor's report, which he said were subject to protections, or "privilege", letting parliament hold inquiries and debates without interference.

"Of course, the court dutifully fulfilled its obligations to make a determination as to whether or not that evidence was covered by privilege," Senator Patrick said.

"But thus far the parliament has done nothing about the breach.

"It really rests on the parliament to protect its own privileges and rights. It's not something we subcontract out to a court.

"The privilege belongs to the parliament and extends to people when they make submissions to inquiries, or petitions to the parliament."

Thales Australia was contacted for comment on Wednesday night. It has previously rejected the allegations in a written submission to an inquiry into Mr Porter's order suppressing parts of the audit office report. After the defence company complained the information would unfairly harm its commercial interests, Mr Porter ordered the sections to be blacked out as they would undermine Australia's national security and defence if published.

Thales denied tendering or speaking about the documents as set out in laws covering privilege, and said the legislation did not prohibit it tendering to court extracts of the Australian National Audit Office's draft reports.

In Thales' submission to the inquiry, Mr Jenkins said its attempt to stop the report's publication through the Federal Court, as well as its request to the Attorney-General to redact the audit, had been vindicated by Mr Porter's decision to order the suppression.

The Senate's privileges committee has found few people guilty of contempt and has never imposed penalties. Parliament can punish contempt with fines of $5000 for individuals and $25,000 for corporations, and up to six months imprisonment for individuals. A court can overturn punishment imposed by parliament for contempt.

Senator Patrick called for parliament to "find its mojo" in exerting its power in Thales' case, and referred to reports of a recent British parliamentary committee decision to compel the founder of a US software company, Six4Three, to hand over internal Facebook documents during a business trip to London.

Mr Porter's largely unprecedented decision to suppress parts of the national audit office's report initially stopped the public from learning about its finding Australia could have saved hundreds of millions of dollars if it bought the vehicles through a United States program.

Auditor-general Grant Hehir told an inquiry hearing he was concerned other agencies were also starting to try having parts of his reports blacked out.

He revealed that since Mr Porter's decision, the Home Affairs Department and the Australian Criminal Intelligence Commission had already followed suit by flagging they could try having his reports into their projects redacted.