The 19-year-old star joked that she smokes "way too much weed" - slang for marijuana - when her pals presented with a Bob Marley birthday cake at the bash at Beacher`s Madhouse inside the Roosevelt Hotel in Los Angeles last Tuesday (22.11.11).
In a video obtained by website The Daily, she is seen saying: "You know you`re a stoner when your friends make you a Bob Marley cake. You know you smoke way too much f**king weed!"
Alluding to an incident last year when footage emerged of Miley smoking a bong water pipe which she later claimed contained the legal hallucinogen Salvia, her pal Kelly Osbourne replied: "I thought salvia was your problem!"
A spokesperson for the former `Hannah Montana` star has denied she was referring to her own drug use in the video.
They said: "It`s all been taken out of context. The cake was a joke and Miley`s response was intended to be sarcastic."
Kelly - who organised the bash for her friend - later took to her twitter page to defend the comments in the clip and slam the person who leaked the footage.
She wrote: "Let me make something very clear after @MileyCyrus salvia incident we started calling her Bob Miley as a JOKE! The cake was also A JOKE.
"It makes me sick that @MileyCyrus so called `friends` would sell her out and lead people 2 believe she is someone that she is not!
"U guys if @MileyCyrus is not recording/filming/touring she is works everyday how could she possible do all that if she was a stoner! #think.` (sic)"