Whitney Houston's Australian comeback is under fire after fans criticised the opening night of her Australian tour claiming the singer sounded 'croaky and appeared 'disorientated'.

The American star struggled through the opening night of her first Australian tour since 1988, and was left breathless and exhausted after just two songs at her show at the Brisbane Entertainment Centre, it was claimed.

And even more bizarrely, the 46-year-old took a 20 minute break to catch her breath mid-way through the show.

Poor show: Whitney Houston's Australian comeback tour got off to a poor start after fans said the singer sounded 'croaky' and appeared 'disorientated' in Brisbane last night

After half a dozen songs she left the stage for twenty minutes to take a break, bringing on her brother, Gary Houston, to sing in her absence.

The band and backing singers then performed an energetic version of one of her biggest hits, Queen of the Night, from The Bodyguard soundtrack.

One fan interviewed on Australian TV after the show said: 'It was a disgrace.

'She can't sing. She didn't sing one song properly.

'She was disorientated and she needed a 20-minute break. It was the first concert I have walked out of in my life.'

Another fan said: 'She couldn't entertain a dead rat, to be honest.'

Comfort break: Houston, we have a problem: Whitney took a 20 minute break in the middle of her show after sounding breathless

Other fans took to Facebook and Twitter to complain about the 'croaky' quality of her voice. '

'We just got back from Whitney Houston concert in Brizzy and I feel so sorry for her. She sounded croaky,' fan Rick Crystal said on Facebook.

'#whitneyhouston should have toured 15 years ago. Voice not what it used to be,' adavidholloway said on Twitter after the concert.

Some fans said they would be demanding their money back.

'The multi-award winning singer appeared disoriented and failed to properly name some of her backing band as she introduced them to the audience, ' wrote the Australian Associated Press's music reviewer.

'But the final act faltered at the finale when she croaked her way through I Will Always Love You, pausing to get a drink and towel herself down just as she was about to hit the song's epic high note, which she turned into a soft coo,' he added.

Surprised: The singer's spokesperson said the star was 'surprised' at the criticism and denied she was suffering from any health-related issues

Whitney has sold more than 170 million albums, singles and videos, with her career soaring through the 1990s, but was later almost consumed by her heavy drug addiction and abusive relationship with singer Bobby Brown.

Meanwhile the singer's spokesman Andrew McManus said Whitney was 'surprised' by the negativity and rejected rumours the 46-year-old was ill after the performance.

'It was not a train wreck,' McManus said. 'She was hitting most of the notes, yes her throat was a little croaky.

'Her health is fine but she's also not 22 years of age anymore.'

The Australian concerts are part of her comeback "Nothing But Love" tour which kicked off at the end of last year.

'She was not fit to perform,' wrote one on the Courier Mail newspaper's website.

'She seemed to be on another planet and the concert was laughable.'

US pop icon Britney Spears attracted the ire of Australian fans in November, with concert-goers reportedly walking out of her show because she was lip-synching.

The tour is scheduled to continue in Sydney, the Hunter Valley, Melbourne and Adelaide.