'Rapper' Joaquin Phoenix stunned millions of viewers in America last night when he gave a disastrous interview on the David Letterman show.

The singer was on to talk about his new movie 'Two Lovers' – the film he claims to be his last – and appeared completely disinterested from the offset, often giving just one or two word answers throughout.

Letterman originally found the car-crash interview funny, but eventually resorted to poking fun at the Oscar nominated star.

Letterman joked towards the end of the interview: "Joaquin, I'm sorry you couldn't be here tonight."

Speculation is already rife that Phoenix was merely acting during the interview.

As reported yesterday, Phoenix quashed rumours that the new rap career is a hoax and confirmed he's turning his back on movies for good.

Explaining to Associated Press that he's not going to go back on his word, he said: "I'm not one of those people, like, when I break up with my girlfriend, I don't ever see her again. I see her as friends, but do I ever think about getting back together? No, when I do something, I do it. So I have no intention."

You can see the hilarious interview below:

(by Scott Colothan)