Nikolas Stefanatos, 27, accused of splashing acid on his girlfriend Tanya St. Arnaud last weekend, made a brief appearance in a Montreal courtroom Friday morning amid tight security.

Stefanatos was arrested on Monday and charged with aggravated assault and assault causing bodily harm after police say a bucket of acid was splashed on his girlfriend, 29-year-old Tanya St. Arnauld, in Longueuil following an argument.

The incident left the woman with no hair and third degree burns to her head, face and chest.

St. Arnauld is being treated at the burn unit of the Hotel Dieu hospital in Montreal.

Her brother attended Stefanatos’ court appearance Friday and told reporters that she is now awake and is slowly recovering after being in a medically induced coma earlier in the week. He said her eyes and most of her face are intact and that the worst burns are on her arms.

"I don't know how he feels.  I don’t know if he feels remorse about what he did, or if he's sad because he's in trouble,” said the victim’s brother Maxime Gosselin.

But his thoughts are more with his sister.

"We're not sure if she's seen herslf in the mirror but she's angry. She has seen her arms and everything," said Gosselin, who also reports that he advised his sister to break up with her boyfriend before the attack. "I told her before, a week before it happened. She didn't really talk about her relationship that much."

Stefanatos' lawyer did not ask for bail at the hearing Friday.

“We have to check on some things before we can come up with a bail proposal,” said defense lawyer Melanie Gregoire.

But the prosecutor wants to keep the man behind bars.

“We maintain our objection to the release of Mr. Stefanatos,” Crown Prosecutor Erin Kavanagh told CTV Montreal.

It was still unclear what kind of acid had been thrown at her. Police said Stefanatos had been using it to clean the concrete around the couple’s Ste-Catherine Street home.

Police believe they have identified the substance used in the alleged attack but are awaiting laboratory results to release specifics.

"It's a house cleaning product, a bit like Drano or something," said Const. Martin Simard of the Longueuil police.

The bail hearing was postponed to Sept. 12. Stefanatos faces three charges including aggravated assault, for which the maximum sentence is 14 years.

St. Arnauld is at a Montreal hospital with burns covering 70 per cent of her body. Her face is wrapped in bandages. She has been woken from a medically induced coma and has been able to communicate to some members of her family.

Her injuries are not considered life-threatening.

Police say that after the couple spent an evening with friends, a dispute erupted between Stefanatos and St. Arnauld.

She was allegedly first splattered in ketchup and mustard, then she left the couple's apartment for a few minutes to see friends. The more serious attack allegedly occurred upon her return.

Investigators plan speak to St. Arnauld next week.

-With files from The Canadian Press