Australia tax commissioner Chris Jordan insists he has sufficient powers to hunt down tax dodgers, with a new report showing one in three privately-owned businesses paid no tax in 2013/14.
The Australian Taxation Office on Tuesday released details of more than 300 privately-owned businesses with an income of $200 million or more, in its aim for greater transparency.
Like its December report relating to large corporations, 30 per cent of private businesses paid no tax.
But Mr Jordan said the ATO is on the case for anyone rorting the system.
"We absolutely have an extraordinarily strong focus, we've got powers, we've got the law to back it up, we have got the sophisticated tools now," he told Sky News.
Michael Croker, head of taxation at Chartered Accountants Australia and New Zealand, said there are a number of reasons why a company pays no tax - the carry forward of losses, high business deductions or the tax-free treatment of dividends from offshore subsidiaries.
But Labor said such revelations come at a time when the Turnbull government appears to be mulling a company tax rate cut.
"It says everything about Malcolm Turnbull's priorities that he would put company tax cuts at the centre of his budget, even as so many big firms appear to be dodging their fair share," shadow assistant treasurer Andrew Leigh said in a statement.
Greens MP Adam Bandt agreed.
"The treasurer should be asking if our corporate tax laws are tough enough, not trying to cut the company tax rate," he said.
But CPA Australia head of policy Paul Drum said it is "opportunistic at best and lazy at worst" to link the two concepts.
"The possibility of reducing the corporate tax rate has nothing to do with the way a private group is structured and whether it is paying the appropriate amount of tax," Mr Drum told AAP.
Mr Croker was critical of the report, saying it shed little light on the tax affairs of the entities involved and could not be described as transparency.
"If misinterpreted, the data can in fact incorrectly suggest the ATO is not doing its job and imply that taxpayers who have not breached any tax laws are somehow immoral," he said.
The 321 firms involved in the report had income tax payable of around $2 billion in 2013/14 with a further $1.6 billion reported by their associated entities.
Since 2013, more than half of these companies have been subject to some form of ATO engagement to better understand their tax position.
As a result, 25 per cent of them had additional assessments totalling more than $530 million in liabilities, the report said.
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