Mariah Carey has been feuding with the rapper for years [Image: Getty Images]

Mariah Carey's Twitter has been hacked by prankster who made a series of racial slurs and declared Eminem "as a little penis".

The superstar singer's account was taken over by an Internet fraudster last night who tweeted a series of shocking messages.

Mariah, 49, seemed to be unaware of the breach as the troll posted tweets featuring the N-word, and joked about her rumored romance with rapper Eminem.

One of the tweets took aim at the star's manhood, writing: "Eminem has a little penis," with another adding "Eminem can still hold this p***y."

The singer later discovered the hack and deleted the tweets before adding a message about the stunt, writing: "I take a freaking nap and this happens?"

Mariah was previously embroiled in a feud with Eminem after he claimed to have bedded her in the lyrics to his track Superman.

He rapped: "What you trying be? My new wife? / What, you Mariah? Fly through twice."

Eminem claimed to have bedded Mariah - but the singer denied it

Eminem referenced her again in When the Music Stops, rapping: "I done came way too far in this game to turn and walk away, and not say what I got to say.

"What the f**k you take me for a joke? You smokin crack? Before I do that, I'd beg Mariah to take me back."

However, Mariah insisted she'd never had a relationship with the star.

READ MORE: Eminem responds to Nick Cannon’s diss, demands apology

During an appearance on Larry King Live, she said: "I hung out with him, I spoke to him on the phone. I think I was probably with him a total of four times.

"And I don’t consider that dating somebody."

The messages shocked her fans [Image: Twitter]

Mariah later mocked Eminem during one of her stage shows, and he hit back by playing voicemails, said to be from the singer, during his own concert tour.

They continued to swap insults over the years, with Eminem branding her a "f*****g liar" in his song Jimmy Crack Corn and a "f*****g whore" on agpipes from Baghdad.

READ MORE: Mariah Carey and three other celebs who chilled till marriage

Mariah is said to have responded with her own diss song, Obsessed, but she later insisted it wasn't about the rapper.

It sparked a furious response from Eminem in his track The Warning, which openly attacked Mariah.

In the song, he rapped: "Shut the f**k up before I put up all the phone calls you made to my house when you were Wild N' Out before Nick [husband Nick Cannon], when you was on my d**k and give you something to smile about."