LOS ANGELES (AFP) - Iggy Azalea has soared to stardom as a rare white woman in hip-hop, but her meteoric rise has triggered a backlash that reveals much about the music business' fault-lines on race and gender.

The 24-year-old Australian, who released her first full album just nine months ago, is up for four Grammy awards on Sunday, including the prestigious Record of the Year for her smash hit Fancy.

But even as Azalea wins plaudits from the industry and packs arenas, detractors see her as uncanny or even offensive - a white, blonde woman who raps in an accent that is identifiably African American.

Her most vociferous critic has been fellow rapper Azealia Banks, a black woman who has accused Azalea of mocking African Americans.

Banks, who has never been nominated for a Grammy, charged that Azalea - whom she taunted as "Igloo Australia" - shied away from issues important to the black community such as police brutality.

"When they give these Grammys out, all it says to white kids is, 'Oh yeah, you're great, you're amazing, you can do whatever you put your mind to.'

"And it says to black kids, 'You don't have s**t - you don't own s**t, not even the s**t you created for yourself,'" Banks said in a radio interview.

Azalea - who moved to the United States as a teenager to pursue her hip-hop dreams and has been romantically linked to African American men - has denounced Banks as a "bigot."

"There are many black artists succeeding in all genres. The reason you haven't is because of your p**s poor attitude," Azalea wrote on Twitter.

HIP-HOP NOW GLOBAL

Hip-hop has gone global since its birth in New York in the 1970s - and Azalea is hardly a trailblazer as a white rapper.

The all-time best-selling rapper - Eminem - is white, as are Macklemore and Ryan Lewis, the duo who won four Grammys last year.

But a more unique factor is Azalea's gender. No women, black or white, have come close to achieving the sales of hip-hop's leading men, some of whom are notorious for misogynistic lyrics.

James Braxton Peterson, a scholar of hip-hop at Lehigh University, said that the music's US audience was now predominantly white - but also male - meaning that Azalea was able to connect with a ready audience of white girls and women.

"Hip-hop culture is a black American art form that, much like jazz and the blues and other art forms before it, has transcended the origins of its emergence," Peterson said.

Peterson said it was unrealistic to stop the globalisation of hip-hop, which has become a potent political force in parts of the world as diverse as France, Ghana and the Gaza Strip.

Yet hip-hop, by its very nature, draws more questions about artists' identities, he said.

"In most other musical forms, if somebody else writes your lyrics, that's fine, that's pretty normal. But in hip-hop, if someone else is writing your lyrics, it calls into question all sorts of questions of authenticity," he said.

Azalea has been dogged by accusations of using ghostwriters. Nicki Minaj - one of the most acclaimed female rappers - was widely seen as criticising Azalea last year when she said that the world should know, "When you hear Nicki Minaj spit, Nicki Minaj wrote it."

The Trinidad-born Minaj later accused the media of putting words in her mouth and has congratulated Azalea on her success.

WHAT IS GENUINE?

It will never be known if Azalea would have achieved similar success if she rapped in Australian brogue. British hip-hop artists such as The Streets and London Posse kept their accents and enjoyed success, although not on the massive scale experienced by Azalea.

Despite the charges of inauthenticity, Azalea - like many rappers - has injected herself into the music. In Work, one of her first songs, she raps of her struggles to start in hip-hop and declares: "People got a lot to say / But don't know s**t 'bout where I was made."

But her lyrics have also faced close scrutiny. She apologised for another song in which she described herself as a "runaway slave master" - a phrase she insisted was metaphorical and not racist.

Azalea, a prolific user of Twitter, recently wrote she was annoyed by strangers trying to "set the guidelines for how I should act or what's genuine for me."

"I'm myself, as strange as I may be, daily," she wrote.