Joaquin Phoenix has apologised to David Letterman for his infamous "horrible" appearance on The Late Show.
The 50-year-old actor memorably appeared on the 78-year-old broadcaster's talk show in 2009 to promote Two Lovers while in character for his mockumentary I'm Still Here -for which he had publicly announced he was giving up acting to focus on a hip-hop career - and he admitted he felt "stuck" because of his commitment to the project.