Titus Day was arrested on Wednesday.
Guy Sebastian's former manager has been charged by police on fraud offences.
As ABC reports, it is alleged Titus Day defrauded the Australian singer of $1.15 million between December 2013 and April 2020 and did not tell Sebastian about money he was owed from work during that time.
Day, who co-runs Six Degrees Management, was arrested at his Bondi home on Wednesday and is facing 61 counts of dishonestly obtain financial advantage by deception.
Sebastian and Day's 12-year relationship ended in late 2017 and by December 2018, they both launched lawsuits against eachother.
The inaugural Australian Idol winner alleged at the time that he was owed over $200,000 in live performances fees, including The X Factor spots and supporting a Taylor Swift tour.
Meanwhile, Day alleged he is owed $800,000 from Sebastian.
Don't miss a beat with our FREE daily newsletter
"Guy terminated the management contract after 11-and-a-half years without notice and then refused to pay me commissions on any work that I did, even for events that had been completed," Day said.
"That crippled my business."
Day has been refused bail to appear at Waverley Court this morning.