A woman from Longueuil, Que., is in a coma, with serious burns to her upper body, after she was attacked with acid Sunday. 

Police say the man arrested in the attack is her boyfriend, who is to appear in court for a bail hearing on Friday.

Nikolas Stefanatos, 27, of Brossard, Que., was charged with aggravated assault. In his first court appearance Monday, his bail hearing was held over.

Longueuil police spokesman Martin Simard called the attack a case of conjugal violence. He said police were called to the woman's apartment on Ste-Catherine Street in the Montreal suburb at around 5 a.m. ET Sunday.

The woman, identified as Tanya St-Arnaud, 29, had burns to her face, arms and upper body, caused by a household product containing acid, Simard said.

"We know that the product is very dangerous for the skin if it's not diluted," Simard said. "The woman was taken to the hospital."

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Nikolas Stefanatos, 27, is charged with aggravated assault and will be back in court in Longueuil, Que., on Friday. (Facebook)

Simard said authorities do not fear for her life, but the woman is in a coma — likely medically induced — so it will be some time before investigators are able to interview her for her version of the events.

Simard said St-Arnaud's assailant fled the apartment immediately after the attack, but was picked up by police a few hours later.