The Kathleen hitmakers had been due to kick off the four-show trek with a performance in Melbourne on Wednesday (22Jul15), but just hours before, the musicians announced the gigs would no longer be going ahead.

A post on their page on Wednesday morning reads: "It is with huge regret that, due to illness in the band and crew, Catfish And The Bottlemen will not be playing their planned shows this week in Australia and Japan; including Splendour in the Grass and Fuji Rocks festivals.

"The band are obviously absolutely devastated not to be making the trip and hope fans will understand."

Festival organisers at Australia's Splendour in the Grass have moved quickly to find a replacement for Catfish and the Bottlemen, drafting in local dance act DZ Deathrays.

No further details about the nature of the band's illness have been revealed, but the stars are expected to resume their tour in North America next week (31Jul15).