The former reality television star allegedly helped move $250,000 in stolen ATO funds into a company in her name, The Daily Telegraph reports.
Her then-boyfriend, Daniel 'Big D' Rostankovski, was one of nine people arrested in May. He is charged with defrauding the Commonwealth and allegedly stealing over $100 million in taxpayers' money.
A tendered affidavit from a federal agent alleges Mr Rostankovski created the company in his partner's name to launder the money, and allegedly used it to buy her expensive gifts including a boat and luxury car.
Ms Constantopedos has not been charged with any offences.
Rostankovski allegedlly pedalled the money through a company in the singers name, called Mermade Holdings.
Documents reveal she agreed to have the money 'disguised' as loan repayment from 2015, despite the company, of which she is the loan shareholder and director, only being established in 2016.
In November of last year, Mermade Holdings received another 'loan repayment' of $35,000, and the same day spent $35,000 on a 'boat payment', court documents reveal.
Ms Constantopedos was a member of one of the final four groups remaining on the X-Factor in 2011 as a member of singing trio Best Wishez. Neither of the other two band members are alleged to be involved with the ATO case.
This article originally appeared on New Idea.