This comes a day after Fairfax Media revealed details about Chevron's alleged $258 million tax avoidance scheme, which tax authorities claim involved an elaborate system of loans and inter-party payments worth billions.

Speaking in Washington before chairing a G20 finance ministers meeting, Mr Hockey said member states were determined to use all available resources to close tax loopholes.

"Let me be very clear, a tax cheat is a thief," he said.

He said the Chevron case was a matter before the courts but defended the ability of the Tax Office to take on disputes.

"Taxpayers have the opportunity to challenge decisions by the Australian Taxation Office in court and the Australian Taxation office has the opportunity and the resources to defend its position," he said.

The opposition has slammed the government's comments as rhetoric in the face of massive budget cuts to the Tax Office and the government's failure to introduce a package of Labor reforms.

"The Treasurer has backed down on $1.1 billion of Labor measures tackling multinational profit shifting," shadow assistant treasurer Andrew Leigh said.

"At the same time he's slashed $189 million from the Tax Office's staff budget, sending 3000 skilled tax officers out the door."

"So, in fact, Joe Hockey is giving the Tax Office neither the laws it needs to tackle tax avoidance, nor the resources to enforce existing ones."

Greens leader Christine Milne said the Chevron case "shows just how these multinational corporations have been ripping off the Australian taxpayer for so long".

A report by the independent Inspector-General of Taxation raised serious concerns about an exodus of experienced staff from the ATO at a time when money flowing between Australian companies and their foreign subsidiaries topped $270 billion.

The cuts will see the agency lose more than 10 per cent of its workforce over the next 12 months, according to budget papers.

But Mr Hockey said there was "no shortage of resources in the Australian Taxation Office, none at all, particularly when it comes to litigation."

"I will give the Australian Taxation Office whatever laws it needs to ensure that the integrity of our taxation laws is upheld," he said.

Mr Hockey's comments come as concern around corporate tax avoidance reaches fever pitch ahead of the G20 leaders' summit in Brisbane next month.

Chevron is the latest multinational company to be accused of dodging tax in Australia – a claim it is disputing in court.

The ATO alleges the oil giant used transfer pricing tactics to avoid up to $258 million in Australian tax over several years.

The dispute is being fought by Chevron in the Federal Court of NSW amid a whirlwind of debate about whether companies are paying their fair share of tax.

Other corporate leaders have weighed into the debate including News Corp chief executive Robert Thomson.

21st Century Fox, formerly called News Corporation, was named in a report by the Tax Justice Network as paying less than 1 per cent tax.

"As a CEO representing shareholders, you like taxes to be lower," Mr Thomson said at a talk at RMIT.

Transurban chairman Lindsay Maxsted also defended his company's tax record, saying large infrastructure companies relied on investments that reduced their tax in the short term.

"It follows that over a 40-year period we're going to make more profits [and] more taxable income than we are in the early years," he told shareholders.

with John Kehoe, Madeleine Heffernan and Alana Schetzer