Joaquin Phoenix's most recent movie director feels responsible for his bizarre career change.

The Oscar-winning star has come under intense scrutiny following his decision to become a rapper, which has seen him grow an unkempt beard and appeared disheveled and incoherent during recent interviews.

Joaquin Phoenix has sparked fresh concerns for his mental health after a bizarre appearance on a TV show.

The Oscar-winning actor, who recently quit Hollywood to launch a music career, looked disheveled and wore dark sunglasses during his awkward interview with talk show host David Letterman last night.

Joaquin Phoenix is "pretending" to have a nervous breakdown. The star - who is filming a documentary about his transition from acting to hip-hop music - is apparently faking his recent public outbursts for the film, directed by "Gone Baby Gone" actor Casey Affleck.

A source told Entertainment Weekly magazine: "He said, 'It's a put-on. I'm going to pretend to have a meltdown and change careers, and Casey is going to film it.'"

Joaquin Phoenix reportedly "stormed out" before a Las Vegas concert after losing his cool with a film crew. 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."

Eva Mendes says her butt wins people Oscars. The 28-year old actress has joked her shapely rear was behind Denzel Washington winning an Academy Award for "Training Day," and thinks she should get credit if her latest film "The Spirit" wins an Oscar.

Eva, 28, said: "I don't do nudity just for the sake of it. I've only done it twice before and that was opposite Joaquin Phoenix and Denzel Washington. And Denzel won an Oscar for it... Well not for our scene! For the movie."