Tanya St. Arnaud (pictured) was doused with acid by her boyfriend Nikolas Stefanos.
Nikolas Stefanos was to appear in court for a bail hearing Tuesday after Tanya St. Arnauld, 29, was attacked in the Montreal suburb of Longueuil.
The victim's brother, Maxime Gosselin, told QMI Agency the couple had been drinking with friends on Saturday evening and the attack happened after the neighbours left the apartment.
"They fought. He was jealous about her girlfriend's (male) friend who was there," said Gosselin.
He said Arnauld went across to a neighbour's place after her boyfriend began to vandalize the apartment.
"She told her to stay and that she would call the police, but (Arnauld) returned home to calm him down," said the brother.
A boiler that stored the acid was sitting at the top of the stairs, and the scalding substance was dumped on top of the woman, Gosselin said.
"(It was) thrown on her face, chest, everywhere," he said.
Arnauld ran to her neighbour's in a panic.
"She was screaming," her brother said. "She hid in the bathroom. As she rinsed her skin it melted, it literally fell off. She was suffering."
The woman was transported to a burn unit in Montreal with serious injuries.
"She's all wrapped up, she has no hair," said Gosselin. "She had acid in her eyes, above her breasts, her back, legs, and she has bruises and scratches."
The couple had fought often during their six months together, said Gosselin.
Police had not been able to interview Arnauld as of Tuesday due to her injuries.