A screengrab of the image Sia shared on her Instagram account. Picture: SiaMusic/Instagram

Sia has shared a nude photograph of herself on social media after discovering that someone was trying to sell the image.

The 41-year-old musician was shocked to learn that a photo of herself was being distributed for profit, and instead of letting herself get caught up in the scandal, she took the opportunity to post the photograph for free on Instagram.

Sia uploaded the photograph - which is a blurry paparazzi shot of the 'Chandelier' hitmaker's bare bottom - to the photo sharing app on Monday night, where she told fans to "save their money" in an attempt to discourage them from buying the image.

She captioned the snap: "Someone is apparently trying to sell naked photos of me to my fans. Save your money, here it is for free. Everyday is Christmas!"

The 'Cheap Thrills' singer is known for being reclusive, and has often been seen wearing big wigs or accessories to cover her face during public outings and performances.

In 2015, producer Greg Kurstin explained that Sia's decision to stay secretive helps her to deal with her fame in her own way.

He revealed: "It's not easy being in the spotlight, and she got to a place where she wanted to look out for her health and do what's best for her. There's a negative side to being an artist, and she wanted to be more in control of her life."

And the star herself previously revealed she dislikes being famous, because it makes her "crazy" and is "bad for [her] self-esteem".

She said: "It literally f**ks with my sanity. I stop feeling authentic because I'm trying to find ways to say the same thing differently. And after a while, you can't. It becomes bad for my self-esteem.

"People say, 'Enough of this s**t where she doesn't show her face'...I'm trying to do this differently, for serenity. And it's a fun game for me as well. I have nothing to lose. 

"But of course I want to be loved. So when people say, 'Show your face, you're not ugly.' I want to say, 'I know. I'm not doing it because I think I'm ugly; I'm trying to have some control over my image. And I'm allowed to maintain some modicum of privacy. 

"But also I would like not to be picked apart or for people to observe when I put on ten pounds or take off ten pounds or I have a hair extension out of place or my fake tan is botched. Most people don't have to be under that pressure, and I'd like to be one of them."