US rapper Kanye West will make a surprise appearance at this week's South By Southwest festival (SXSW) in Austin, Texas, according to reports.

The Associated Press news agency also claims Metallica and Outkast's Big Boi will play secret shows.

Big Boi is expected to preview his forthcoming solo material at the event.

The SXSW festival typically showcases new bands, although the event has a history of staging high profile surprise performances.

(by Jason Gregory)