Labor leader Bill Shorten has suggested an alleged $165 million tax fraud, potentially one of the biggest cases of white collar fraud in Australian history, helps build the case for a federal corruption watchdog.
Prime Minister Malcolm Turnbull on Wednesday congratulated the Australian Federal Police for the investigation, declaring the government had "zero tolerance for this type of conspiracy, this type of fraud, this type of abuse of public office".
Senior federal police and Australian Taxation Office officials are likely to be bombarded with questions on the matter at next week's Senate estimates hearings. A parliamentary inquiry is also on the cards.
Seven alleged syndicate members have been charged, including Adam Cranston, 30, and his sister, Lauren Anne Cranston, 24. Their father, ATO deputy commissioner Michael Cranston, has been issued a future court attendance notice for the charge of abusing his position as a public official.
Mr Shorten said while all facts of the case needed to be established, there were questions of competence for the government to answer.
"It would be remiss of me to comment on the individual matters, although they are clearly very concerning. I don't want to impinge upon anyone's rights, nor do I want to impinge upon the prosecution if the wrong thing's happened," he said.
"But clearly here, down the track there will have to be questions of competence for the government to answer. And I also think it makes Labor's support for having a Senate committee investigating the merit of a National Integrity Commission seem quite on the money."
The Greens have long backed the establishment of a federal corruption watchdog.
Mr Turnbull described the alleged fraud as "very, very much to be regretted".
"People who break our laws - whether it is endeavouring to defraud the Commonwealth and the tax system, whether it is planning terror plots, whether it's trafficking in drugs - our police, our agencies will catch them," he said. "Catch them, prosecute them and bring the full weight of the law down to bear on them.
"It is a credit to the police that the matter has been identified and charges have been laid. We are ever vigilant. You cannot be ever complacent about any aspect of integrity in public life or in government. So we have a relentless pursuit of corruption, malpractice, abuse of office. The AFP have a very keen focus on it, I can assure you, as has been demonstrated."
The acting commissioner of the ATO, Andrew Mills, said in a statement he had commissioned an investigation into alleged staff involvement.
"I cannot overstate the seriousness of these matters - Australians must have a tax administration they can trust and the people of the ATO must be of utmost integrity and good judgment," he said.
