Australian Taxation Office Deputy Commissioner Michael Cranston has been caught up in a major tax evasion scheme allegedly involving his son and daughter.
Mr Cranston, 58, has been issued with a court attendance notice for allegedly publicly abusing his position as a senior official of the Commonwealth, the AFP said on Thursday.
He has not been officially been charged, but is due to face Sydney Central court next month.
Four ATO officers are also being investigated, said the AFP.
Mr Cranston's 30-year-old son, Adam, and 24-year-old daughter and seven other people have been arrested over a $165 million tax fraud investigation.
The arrests were made following an eight-month investigation, codenamed Operation Elbrus, with assistance from ATO, Australian Federal Police (AFP) said on Thursday.
"The scale of this allege fraud is unprecedented for the AFP," said Australian Federal Police Deputy Commissioner Operations Leanne Close on Thursday.
It is a significant fraud investigation, financial fraud criminal investigation, that the AFP has led since 2016.
Acting Commissioner of Taxation Andrew Mills told reporters in Sydney on Thursday Mr Cranston had "up until this point... held an illustrious career".
"We do take it extraordinarily seriously and ...it is of concern that a long-standing officer has been alleged to have been involved in this," Mr Mills said.
The ATO was conducting an internal investigation into four officials into whether or not they looked at the material they were unauthorised to do so.
"If you are an officer within the ATO, you have access to those matters only to which you actually are required for the purposes of your job. If you seek to obtain information which is outside that scope, you actually are in breach of the code of conduct," he said.
Ms Close said it appears Mr Cranston's son has asked him to access some information.
"We don't believe that at this point that he had any knowledge of the actual conspiracy and the defrauding," she said.
Assets seized in the past two days by the AFP include 25 motor vehicles - luxury, vintage and racing vehicles - 18 residential properties, 12 motorbikes, in excess of 100 bank accounts and share trading accounts, two aircraft. firearms and jewellery, artwork, vintage wines and at least $1 million located in a safety deposit box.
Adam Cranston, 30, is due to face Sydney's Central Local Court on Thursday morning charged with conspiracy to defraud the commonwealth, while his sister is due to face a Sydney court on June 13.
Adam was arrested at Bondi while his sister was arrested in Picton during 27 raids on homes and businesses across Sydney on Wednesday.
A further six search warrants will be executed on Thursday, said the AFP.© AAP 2017 Image Credit: AAP Image/Paul Miller