Former ATO contractor-turned-fraudster slapped with 18 months behind bars

According to the ATO, Dierens’ fraudulent behaviour was uncovered as part of an Operation Protego investigation after she worked for the ATO between 2019 and 2021, where she assisted taxpayers with income tax, business tax and debt-related matters.

It was made clear by the ATO that Dierens’ fraudulent activity occurred after her engagement with the ATO had come to an end and didn’t involve ATO systems, nor were any systems compromised, as was later identified by the investigation. 

The fraud was committed between February and April 2022 and involved Dierens providing her personal myGov details to associates who lodged seven false business activity statements with the ATO, resulting in refunds totalling $105,000 to which she was not entitled. 

The ATO said Dierens admitted she knew the business activity statements were fraudulent and spent the money she dishonestly obtained on personal items such as clothes, shoes and a vehicle. 

Nicholas Shizas, ATO deputy commissioner, said the ATO expected high standards of integrity and accountability from all staff and took any allegations of fraudulent behaviour or activity by current or former staff extremely seriously. 

“Integrity is at the heart of everything we do. The Australian community expects and deserves the highest standards from the ATO, and we will act decisively when those standards are compromised,” he said.

“We will not tolerate fraudulent behaviour, and we will continue to protect the integrity of the tax and super systems.”

The ATO revealed it had now applied treatment against more than 57,000 alleged offenders as part of Operation Protego, and those involved in this fraud had already been handed in the order of $300 million in penalties and interest. 

“As of 31 October 2025, 144 people had been convicted with a range of sentencing outcomes, including jail terms of up to seven years and six months and with orders made to restrain real property,” Shizas said. 

“The ATO has finalised 64 investigations and referred 54 briefs of evidence to the Commonwealth Director of Public Prosecutions. The figures do not include former ATO staff.”