Lang and producer Ryland Aldrich recently formed production company Pictures, Pictures and have lined up the Untitled Sia Documentary Project, which will give fans a chance to see never-before-seen aspects of the Chandelier singer's life.

Details surrounding the film have yet to be released, but the news comes days after the pop star announced plans to direct her frequent video collaborator, dancer Maddie Ziegler, in new movie Sister, which she wrote eight years ago.

Lang is also working on a documentary about the game of golf after a crowdfunding campaign helped him raise $50,000 (£31,000) towards filming costs.