Multinational firms shifting profits offshore to avoiding paying local taxes should be "named and shamed", the chair of an Australian parliamentary inquiry into the practices said Sunday ahead of the release of a report.

The inquiry has grilled senior representatives from some of the world's biggest firms in the technology, pharmaceutical and mining sectors on whether they were using complex corporate structures to reduce their tax burden.

The push in Australia to crack down on multinational firms has been mirrored in other countries, with Britain in March introducing a so-called "Google tax" on companies that divert profits overseas.

"The worst tax offenders should be named and shamed, they should have to justify publicly why they're taking the stances that they're taking," the inquiry's chairman Sam Dastyari told reporters in Sydney.

The inquiry's report, to be tabled in parliament Monday, is set to call for the disclosure of tax avoidance settlements with the Australian Taxation Office above a certain level -- such as Aus$100 million, the Sydney Morning Herald reported.

"At this point in time, 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 tax office," Dastyari added.
"The more public exposure, the more pressure that's brought upon these companies, the better the policy outcome."

One of the report's 18 recommendations will suggest that even companies with overseas headquarters should disclose their revenue, tax paid and deductions used in Australia, the Herald said.

Firms quizzed by the upper house Senate hearings, including Apple, Google, Pfizer and Johnson & Johnson, said they had abided by local and international tax laws.

Australian Treasurer Joe Hockey revealed earlier this year his government's plans to introduce legislation targeting 30 unnamed firms for shifting profits offshore.

While the Organisation for Economic Cooperation and Development (OECD), a grouping of wealthy nations, has played a key role in international efforts to tackle tax avoidance, such concerns are also shared by developing countries.

The issue took centre stage at a global developing financing summit in Ethiopia last month. The UN's trade and development body UNCTAD has said that such practices were costing poorer countries some US$100 billion a year.