Some of the Australia's biggest corporate tax cheats may be named and shamed by the Australian Tax Office (ATO), under a recommendation believed to be part of a Senate committee report due tomorrow.

The committee, chaired by Labor senator Sam Dastyari, had been investigating multi-billion-dollar tax avoidance by some of Australia's biggest companies, as well as multinationals that operate locally.

Senator Dastyari remained tight-lipped on the exact findings of the report, but said companies dodging tax should be named and shamed.

"You have a series of Australia's most powerful companies fighting against any transparency measure to actually reveal what goes on behind closed doors between them and the [Australian] Tax Office," he said.

"What you have is a handful of multinational companies who have been gaming the system for years.

"Tax evasion, tax avoidance, tax minimisation has real human consequences, because it means the money that needs to be there to support the services we all believe in, isn't there."

Tech giants Apple, Google and Microsoft were among several companies which appeared before the inquiry examining the adequacy of Australia's current tax laws, the work of the ATO and whether more transparency was needed to deter profit shifting and tax avoidance.

Australian mining heavyweights BHP Billiton and Rio Tinto also came under the spotlight, as did the pharmaceuticals sector.

The consensus was similar for all companies involved: they weren't avoiding tax, but were operating and structured in a way to maintain competitiveness in the market.

Senator Dastyari said swift action needed to be taken once the committee report was made public.

"I can't go into the specifics of the evidence given to the inquiry and go to the specifics of the committee," he said.

"The Government has been great on talk, and terrible on action.

"The rhetoric from the Treasurer on this issue has been fantastic to date, [but] his action has been minimal.

"The laws, as they currently stand, mean that Australia's worst tax offenders are able to hide behind privacy provisions."

It was a sentiment echoed by Independent South Australian senator Nick Xenophon, who was also on the committee.

Senator Xenophon said the strength and serious nature of the report would mean the Government could not avoid embracing its recommendations, particularly with regards to large multinational companies.

"Tax law needs to be simplified as well as being beefed up," he said.

"The Tax Act at the moment is a big ugly doorstop, and we need to improve it.

"There are some multinational companies out there that have been treating Australian taxpayers [and] successive Australian governments as mugs when it comes to their ability to pay next to no tax.

"Having a naming mechanism, I think, will sharpen the thinking of some of these multinationals who are worried about their corporate reputation."