Former Disney child star Miley Cyrus has defended her new hip-hop-infused style and her transition into the rap world after being accused of trying to act black.

The 20-year-old singer, who has publicly shed her good girl Hannah Montana image to become the most famous twerking sensation in the world, has been labelled a "ratchet white girl," and accused of being a wannabe after her reinvention.

She faced fresh criticism this week after posting a preview of her collaboration with rapper French Montana on her Facebook page.

In the one-minute clip, the We Can't stop hitmaker can be seen in the studio working on a remix of his hit song, Ain't Worried About Nothin. She adds vocals to the hook and also raps a verse featuring Molly and Versace as well as an ode to the "thick girls".

Her bold lyrics included the lines: "B***h I ain't worried about nothin,

On the day I dropped my video,

I got three thick girls in my video,

Got that molly and you know that I never stop,

Think I'm turnt up wait until my album drops,

Versace, Versace, Versace,

Fashion week you can find me in New York,

Posing for the paparazzi,

In my all-white like French Montana,

Oh sh**, there goes Hannah Montana."

Within minutes of the snippet hitting the net, the online community accused the white pop star of trying to act black by dropping rhymes.

"Miley stop trying to act black B***H!!!!" one view said.

Another wrote: "Suburban, white, child-star trying to act hard. smh."

Cyrus, who has been trying to distance herself from her Hannah Montana days in recent months, reacted to the backlash by telling her haters on Twitter: "#BANGERZ will be an INSTANT CLASSIC. i know what color my skin is. you can stop with the friendly reminders b***h."

Her fifth studio album, Bangerz album is due out later this year.