A spokesman for Dendy films told the Sydney Sunday Herald "a few things have come up," when asked if the actor would return home for the film's opening.
"It's still up in the air as to when or if it will happen," the spokesman said.
Sources told the newspaper Ledger was still very angry about being sprayed with water pistols by paparazzi at a Sydney red carpet event. Ledger's girlfriend, Michelle Williams, was also said to be "very distressed" by the incident.
Ledger put his Australia home up for sale after the spraying and told friends he planned to move overseas permanently.
Ledger's co-star in "Candy," Abbie Cornish, has said she planned on doing a quick Australian tour when the film opens May 25.