Guy Sebastian's former manager Titus Emanuel Day is fighting his conviction after a jury found he embezzled more than $650,000 from the pop star.
In November last year, the then 49-year-old was sentenced to up to four years in jail and ordered to repay about $624,000 which was fraudulently taken from the Australian Idol winner over eight years.
Day faces at least two years and six months behind bars and will be eligible for parole on May 16, 2025. His full prison sentence expires on November 16, 2026.
A NSW District Court jury found the former manager guilty of 34 fraud charges and not guilty of a further 13 charges in June last year.
With payments for Sebastian's performances sent to trust accounts held by Day's firm 6 Degrees, the talent manager failed to remit what was owed to the pop star from 2009 until November 2017, when the pair fell out.
Funds owed included royalties, performance and ambassador fees, including for a wedding in Venice, singing at a Taylor Swift tour, an ambassadorship for Dreamworld, and playing at a New Year's Day Big Bash cricket event.
Day has taken his challenge to the NSW Court of Appeal, where it was briefly heard on Thursday.
The appeal will seek to overturn the conviction and, if unsuccessful, will not attempt to change his sentence.
Sebastian has also filed a civil suit against his former manager which has been stayed pending the outcome of the criminal proceedings.
The appeal hearing will take place on June 23.
