A fatal attack on a young international student may have been witnessed by her friend online, Toronto police said Sunday afternoon.

Homicide Det. Sgt. Frank Skubic told reporters at a news conference that the 23-year-old York University student signed on to an online chat to speak with her friend overseas at about 1 a.m. Friday morning.

A short time later, she answered a knock at her door. A man walked in and asked if he could use the woman's cellphone. 

"Investigators cannot exclude the possibility that the deceased knew or was familiar with the man, however the man was unknown to the online witness," police said in a news release issued after the news conference.

The suspect and the young woman struggled. Skubic said part of the struggle took place out of the web camera's range but that her friend was able to see a suspect before the man shut the computer closed.

The computer, believed to be an IBM ThinkPad T400, is now missing, police said.

The friend described the suspect as a tall, white man with a muscular build with medium-length brown hair that was styled messy in the front but neatly groomed in the back. The suspect was wearing a blue crew neck T-shirt. He is believed to be between 20 and 30 years old.

"We want to talk to the man," Skubic said. "We're asking him to make himself known."

The woman, who has not been publicly identified, was found naked from the waist down. However, Skubic said there were "no overt signs" that she had been sexually assaulted.

Police also say there were no obvious signs of trauma on the body and that further tests need to be conducted before investigators can say for certain how she died. As a result, police have not yet deemed the woman's death a homicide and for now, are calling it a "suspicious death."

Investigators found the woman's cellphone. It is currently undergoing forensic testing.

Skubic also mentioned that some blogs had picked up the story and were posting a picture of the deceased along with that of a man. That man has been identified and for now remains a person of interest until police can definitively clear him of any wrongdoing.

"He is not a suspect at this time," Skubic said, asking the public and media to refrain from publishing his picture.

Though the woman's basement apartment inside the townhouse at 27 Aldwinckle is still a crime scene, most tenants have been able to return home. Some haven't returned and police are asking them to come to the residence and identify themselves to officers at the scene.