Jan 21, 2009, 11:25 GMT
Joaquin Phoenix reportedly "stormed out" before a Las Vegas concert after losing his cool with a film crew.
An actor first and foremost- Joaquin Phoenix - Joaquin Phoenix Special Appearance at Lavo Nightclub in Las Vegas on January 16, 2009 - Lavo Nightclub at the Palazzo Hotel and Casino - Las Vegas, NV, USA © PRN / PR Photos
The actor-turned-singer is believed to have been furious when Casey Affleck's camera crew - who are documenting Joaquin's transition into music - were late for his sound check at LAVO nightclub last week.
A source said: "He was waiting for Casey Affleck and when the film crew arrived late, Joaquin flipped out. Phoenix yelled at the crew, 'Thanks for being late and f***ing everything up.' He then threw a CD on the floor and stormed out."
Joaquin soon regained his composure and returned to the stage to rehearse his set, leaving onlookers unsure if he was genuinely annoyed.
The source added to the New York Post newspaper: "He came back five minutes later and did the sound check. Nobody can tell if he is for real or if this is all a big joke."
Later that night, the 34-year-old star surprised onlookers by performing three hip-hop numbers.
During his set, a dishevelled Joaquin - who was sporting an unkempt beard and long hair - danced unsteadily and fell into the crowd as he exited the stage.
Joaquin's recent erratic behaviour and bloated appearance has raised concerns for his health.
A source said: "His bizarre behaviour has everyone worried. It's just getting scary."
Joaquin recently admitted numerous people have questioned his desire to pursue a career in the music industry.
He said: "This is my chance to do something straight from the heart and put it out there. Are there people who think it's going to suck? Probably, but I can't worry about that."
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