The Australian Federal Police arrested and charged nine people for their alleged involvement in a $165 million tax fraud conspiracy against the commonwealth.

One of those arrested was the 30-year-old son of Australian Tax Office Deputy Commissioner Michael Cranston. ABC reported the deputy commissioner was issued a court notice for abusing his position as a public official in relation to the fraud, though is not believed to a conspirator.

On May 17, 28 search warrants were executed across Sydney with another six carried out on May 18. The AFP deputy commissioner Leanne Close said the searches were carried out by over 290 AFP personnel.

During an AFP press conference on Thursday, the acting Commissioner of Taxation Andrew Mills said that other ATO employees were being investigated and they were being suspended without pay.

Police will allege the operation involved a legitimate payroll company – run by the accused – accepting money from legitimate clients to process payrolls on their behalf. The money was diverted to seven sub-contractors, who then made payroll payments to individual workers of clients. A portion of the funds that was obligated to be withheld as tax payments to the ATO, was instead allegedly siphoned off to the syndicate members and channelled through companies and trusts for personal use.

The total amount of tax obligations not paid to ATO was estimated to be $165 million, allegedly making it one of the largest white collar crimes in the country’s history.

The arrests occurred at the end of an eight-month investigation, codenamed Operation Morpheus.