Joaquin Phoenix returned to the Late Show With David Letterman Wednesday -- his first television appearance since his wacky February 2009 visit.

Casey Affleck, who directed Phoenix, 35, in the mockumentary I'm Still Here that documented his bizarre antics, has said Phoenix's stunts were part of a hoax -- and Letterman was in on it.

But during their chat, Letterman asked Phoenix if this was true.

“No,” Phoenix flat-out said.

Letterman then asked, “Yeah. Was there a script that you and I were working with?”

“No,” Phoenix responded.

“Thank you very much,” Letterman said. “I was not part of it, was I?”

“Yeah, but, like you said,” Phoenix replied, “I mean, I think that you’ve interviewed many, many people, and I assumed that you would know the difference between a character and a real person, so – but I apologize. I didn’t – I hope I didn’t offend you in any way…”

Letterman shot back, “Oh, no – oh, no, no, no. I was not offended. I’m telling you, it was so much fun. It was batting practice, you know what I mean? Every one of them was a dinger.” 

Phoenix laughed.

"I was looking for a beat down, and I got one…" he said. "I want to thank you for that.”