Sia. Picture: Bang Showbiz
Sia is releasing a new album in 2019, as well as a "feature length musical" which she has written and directed.

The 43-year-old singer - who is famous for hiding her face under a huge wig for anonymity - has revealed she has plans to drop a brand new album next year, which will mark her ninth studio album and her first since her festive themed 'Everyday Is Christmas' album, released in November 2017.

Sia announced the release of her new music - which will also mark her first regular album since 'This Is Acting' in January 2016 - on Twitter, where she also claimed to be working on a "feature length musical", which she said fans can also expect some time in 2019.

When one fan asked her when they could expect some new music, the 'Cheap Thrills' hitmaker responded: "Next year I'm releasing an album and a feature length musical I wrote and directed. Lots of fun things to come! (sic)"

Although Sia hasn't released any albums in over a year, 2018 has still been busy for her as she's teamed up with Diplo and Labrinth in supergroup LSD, worked with Dolly Parton on 'Here I Am' - which featured in the 'Dumplin' soundtrack - and released a standalone single called 'I'm Still Here'.

She also contributed original songs to the soundtrack of 'Vox Lux', which stars Natalie Portman, and which hit cinema screens earlier this month.

Meanwhile, the 'Elastic Heart' singer previously admitted she's struggled with her body image and has "dieted like crazy" to fit the "stereotype" of a pop star.

She said: "I have dieted like crazy over the last 10 years. Trying to fit into the stereotype of, like, 'Hot pop star.' Somebody did say, 'You don't have to be a model. You're actually an artist ... It literally doesn't matter what you look like.'"