"She still came out seven million richer. Why are you protecting her? She will never get the help she needs if we all stay silent!' she added.
Just showing my public support for Johnny Depp. I mean, I'd love him to get clean and stop with the jewelry, but he is clearly the victim after hearing those tapes.
Sia was referring to the $7 million Heard received as a divorce settlement from Depp, which she promptly donated to the American Civil Liberties Union (ACLU) and Children's Hospital of Los Angeles.
It seems Sia is insinuating that Musk gave her $7m after she donated the settlement money.
Neither Heard nor Depp have publicly responded to Sia's comments at this time.
Johnny Depp and ex-wife Amber Heard are heading into a defamation trial. Photo / Getty Images
Depp and Heard met on the set of the Hunter S Thompson adaptation The Rum Diary in 2009, and started dating in 2012 after Depp split from Vanessa Paradis.
The couple were married in a private ceremony at their Los Angeles home in 2015, but Heard filed for divorce in 2016, filing a restraining order against Depp.
The exes have been locked in a contentious legal battle, with Depp filing a $50 million defamation lawsuit against Heard, that was recently delayed.