Aerosmith bassist Tom Hamilton has posted a note on Twitter explaining why he had to leave the band's Australian tour.

He writes, "Thanks to all my fans, friends and loved ones for all the interest in what's going on with me. Had to leave the tour early due to a lung infection. I'm under the best of care and will provide more information within the next couple of days. Thanks again for all the love and support."

David Hull from The Joe Perry Project has flown to Australia to take Hamilton's place, just as he did when Hamilton missed tours in 2006 and '11 when he underwent treatment for throat cancer.