Macquarie Group made eight freedom-of-information requests in one day as part of a legal battle with the Tax Office over a large-scale audit, court documents show.
The blizzard of FOI requests, which covered more than 1500 documents dating back more than 15 years, were filed in an attempt to show efforts by the ATO to levy millions of dollars in tax and penalties on Macquarie should not be allowed because they represented a policy ''U-turn''.
Responding to a BusinessDay report on Tuesday revealing that the tax bill was price-sensitive information that had not been disclosed to the stock exchange, Macquarie told the ASX that the ''matter has been substantially resolved''.
The ATO bill relates to Macquarie's treatment of its offshore banking unit, which is taxed at a concessional rate, in 2006, 2007 and 2008. But the financial services group confirmed it still had outstanding issues with the ATO, on which it held ''appropriate provisions''.
Separately, analysts have raised concerns the ATO might also pursue Macquarie over the 2009, 2010 and 2011 years, when it paid tax at well below the company rate of 30 per cent. In a March 17 note to clients, BBY analyst Brett Le Mesurier said ''the worst-case scenario is a tax bill for 2009 to 2011 of $570 million''.
A Macquarie spokeswoman declined to comment.
ATO auditors have been investigating whether expenses that Macquarie should have been allocated to the offshore banking unit were instead counted against the ordinary domestic bank, where they attract a higher tax deduction.
Federal Court documents show Macquarie's FOI requests were lodged with the ATO as part of a flurry of activity by the group and its teams of lawyers on January 17, 2013.
On that day, the ATO rejected Macquarie's argument that under the ATO's U-turn policy the company should not face additional tax for the 2006-09 years. Under the U-turn policy, any changes in the way the ATO interprets tax laws should only be applied to new tax bills, not to previous years.
The FOI requests, filed by Macquarie's Sydney lawyers Speed and Stracey, covered documents relating to offshore banking units dating as far back as January 1, 1997.
Macquarie was trying to establish that there was an ''industry practice'', approved by the ATO, that supported the way it had allocated expenses.
On March 20 last year, ATO lawyer Regina Rutten knocked back the requests because processing them would take too much time.
She said that although the ATO had not finished searching, it had already identified 373 files containing about 1500 documents.
Between 40 and 50 hours had already been spent searching for documents and more than 30 additional hours would be needed, she said.
After negotiations, Ms Rutten on June 28 released all or part of 373 documents, seven of which Macquarie then tendered as evidence in the Federal Court.
The documents show vigorous debate within the ATO over how offshore banking units should be treated. But by late March 2004 ATO officials believed it might not be legally possible to endorse ways of allocating expenses alternative to a strict legislative formula.
Macquarie tried to use the U-turn argument in the Federal Court case but lost last September.