The rock icon was due to play Sydney on March 9 and Melbourne on March 11.

However ill health has seen him unable to fly to Australia, leaving the event minus a headline act.

“Ozzy recently developed pneumonia and has spent some time in hospital. Thankfully he is now through the worst part, his doctors have advised that he stay at home to recuperate for a full six weeks with no travel,” wife Sharon Osbourne said.

Fans on the Download Facebook page had been anticipating Osbourne to cancel after Japanese dates were axed, and some hoped Iron Maiden could replaced Osbourne as a headline act.

However the festival said replacing headliner Osbourne at this late stage would be “impossible” but have added local rockers Airbourne to the bill.

It still includes Slayer (on their final world tour), Judas Priest, Alice in Chains, The Amity Affliction, Anthrax, Pennywise, Sum 41, Halestorm, Behemoth and more.

Punters with Download tickets can get a merchandise voucher worth $45 in lieu of Osbourne’s cancellation.

Those who want refunds can get them until Sunday February 24 by contacting Ticketmaster customer service team here.

Promoters say punters with tickets should select the “Refund/Exchange” Topic and complete all required fields of the form.