Anthony Mackie says ‘Eminem is an a**hole’ for one surprising detail he included in iconic 8 Mile battle

Anthony Mackie has labeled Eminem an 'a**hole' after sharing the set of 8 Mile together.

The 46-year-old opened up about his time shooting the 2002 musical drama, which is loosely based off Eminem's life, detailing a surprising detail that the artist included during the iconic rap battle they feature in together.

While playing Papa Doc - whose real name is 'Clarence' in the show and is the head of a gang of rookie rappers - Mackie faced off with Eminem's character, Jimmy 'B-Rabbit' Smith, but the rapper went a bit off script.

While appearing as a guest on the Pivot Podcast in March, Mackie explained how the rapper, real name Marshall Mathers, got a little personal with his diss track.

"We're doing the movie and you know, Eminem is just such a brilliant dude, we're on set one day and he's like, 'yo, it don't make sense that we beefing', I was like, 'right', he was like, 'I need something, like on you'.

The moment Eminem disses Anthony Mackie while on the set of '8 Mile' (Universal Pictures)

"So we're talking, we talk for like two hours - like chilling, I'm like, 'alright man I'll see you later'. I go to the casino, the next day we're shooting the battle scene and that's why I'm standing there like you're talking about me you're not talking about Clarence!

"[It] has nothing to do with the character, you're an a**hole Eminem! I'm like, I want to fight this motherf***er! I'm like, 'yes, my parents are still married.'"

Yes, hilariously the 'Without Me' hitmaker, who wrote 'Lose Yourself' for the movie which went on to pick up an Oscar in 2003 for the best original song, was actually rapping about Mackie - not his character.

So, the reaction we saw on screen was as real as it gets - as he was genuinely dissed!

To rejog everyone's memories, here is part of what Eminem said during the rap battle: "Don't ever try to judge me, dude / You don't know what the f*** I've been through.

"But I know something about you / You went to Cranbrook, that's a private school.

"What's the matter, dawg? You embarrassed? / This guy's a gangster? His real name's Clarence."

Eminem, pictured on stage in Detroit last year, took aspects of Anthony Mackie's life and added it to his diss track against his character in '8 Mile' (Aaron J. Thornton/Getty Images)

He continues: "And Clarence lives at home with both parents / And Clarence' parents have a real good marriage.

"This guy don't wanna battle, he's shook / 'Cause ain't no such things as halfway crooks.

"He's scared to death, he's scared to look / At his f***ing yearbook; f*** Cranbrook!"