Did anyone else see this? I honestly believed it was an organized gag, and that Joaquin was to remove his wig at any moment, and begin speaking normally!
Wearing dark glasses and sporting an overgrown beard, the actor refused to make eye contact with Letterman and ignored the US talk show host's questions.
Phoenix, 34, has battled against substance abuse in the past and recently announced his intention to retire from acting and become a musician.
But it has been suggested that the career change is a stunt for a spoof documentary about an aspiring hip hop artist, and that his Letterman interview was carried out in character.
The last part would make sense, as it certainly looked as though he was holding back a smile throughout most of the interview, well - at least that's what I'm hoping.