The former singer for scream-punk act Crystal Castles alleges her band mate abused her and "controlled everything I did" until she quit in 2014.
Alice Glass, who recorded three albums with her band mate Ethan Kath, released a statement detailing years of alleged abuse.
Kath denies her claim, calling it "pure fiction". He says he's consulting a lawyer.
Glass claims Kath became physically abusive during her 10 years in the band, which including several performances in New Zealand as part of the Big Day Out.
"I wasn't allowed to have my own phone or my own credit card, he decided who my friends were, read through my private emails, restricted my access to social media, regulated everything I ate," she wrote.