Lorde has been named the hottest music star under 21 by Billboard.

The 17-year-old Royals singer beat chart stars including Justin Bieber to the top spot in the annual list of the most powerful young music stars.

Billboard said that as well as the New Zealander's many musical accolades, she had "consistently demonstrated an influence that extends well beyond music, championing an image free of touch-ups and letting young girls know that they don't have to dress provocatively to capture the public's attention".

Lorde, whose real name is Ella Yelich-O'Connor, was followed in the 21 Under 21 list by 5 Seconds Of Summer and Justin was third.

Rounding out the top five were Martin Garrix and Fifth Harmony, a girl group put together on Simon Cowell's US version of The X Factor.

Lorde's mum congratulated her by posting a picture of her famous daughter on Instagram, captioned: "@Billboard's 'Most Powerful Young Popstar for 2014' - congratulations, Ella."

The singer tweeted in response: ":) thanks mum (and @billboard )."