Police released a sketch of a man wanted in a sexual assault in November. (Calgary Police Service)

A woman who was seriously injured after a vicious sexual assault in Calgary's Beltline neighbourhood has given police enough information for them to release an updated sketch of her attacker.

The 23-year-old woman was walking alone last November at about 2:30 a.m. when she was approached by a man who tried to engage her in a friendly conversation.

She refused to respond. He then violently attacked and sexually assaulted her in a parking lot on the north side of 10th Avenue, west of 6th Street S.W., said police.

Calgary police released a sketch of the suspect Wednesday and described him as about 25 years old with a thin build and a medium skin tone, perhaps of Indo-Canadian descent. He was about five feet six inches tall with short dark brown hair.

Police said they have reason to believe the attacker was from Ontario and was looking for work in Calgary around the time of the assault.

Crime Stoppers also filmed a re-enactment on Wednesday, hoping it will generate tips from the public.

The woman was new to Calgary and investigators said alcohol was not involved in the attack.

Police reminded people to take safety precautions, such as attending festivals and functions in groups, and to stay in well-lit areas when alone.

Police said sexual assaults in Calgary tend to increase in the summer months, and that drugs and alcohol are often involved and may increase a victim's vulnerability.