The songwriter, 44, Sia threw her support behind FKA Twigs. FKA Twigs real name Tahliah Barnett, 32 – filed a lawsuit against her ex Shia, 34.
She accused Shia of sexual battery, assault, and infliction of emotional distress while they were dating between 2018 and 2019.
Now Sia has spoken out in her support of the actress on her Twitter platform to her fan base.
The Australian singer told her 3.8million followers: “I too have been hurt emotionally by Shia, a pathological liar, who conned me into an adulterous relationship claiming to be single.
“I believe he’s very sick and have compassion for him AND his victims. Just know, if you love yourself- stay safe, stay away.”
In a second tweet, she wrote: “Also I love you @FKAtwigs This is very courageous and I’m very proud of you.”
The Mirror has reached out to Shia LaBeouf’s representative for further comment.
FKA Twigs broke her silence over the lawsuit on social media.
She wrote on Twitter : “It may be surprising to you to learn that i was in an emotionally and physically abusive relationship. It was hard for me to process too, during and after i never thought something like this would happen to me.
“Which is why i have decided it’s important for me to talk about it and try to help people understand that when you are under the coercive control of an abuser or in an intimate partner violent relationship leaving doesn’t feel like a safe or achievable option.”
She added: “My second worst nightmare is being forced to share with the world that i am a survivor of domestic violence my first worst nightmare is not telling anyone and knowing that i could have helped even just one person by sharing my story.
“Here are some amazing charities and helplines that i recommend donating to and calling if you or somebody you know needs support… @freefromorg@ndvh@Sistah_Space.”
The allegations against LaBeouf from FKA Twigs were first reported by the New York Times.
In an email to the New York Times, LaBeouf broadly addressed his past behaviour towards FKA Twigs and another former girlfriend.
He added: “I’m not in any position to tell anyone how my behaviour made them feel.”
The actor continued: “I have no excuses for my alcoholism or aggression, only rationalizations….
“I have a history of hurting the people closest to me. I’m ashamed of that history and am sorry to those I hurt. There is nothing else I can really say.”