Police say they now consider the disappearance of a 36-year-old Markham woman last month to be suspicious and have handed over the investigation to homicide detectives.

Ying Chun (Annie) Li was last seen by her family at around 6 p.m. on June 12 in the vicinity of Denison Street and Markham Road.

According to Li’s brother Jet Hu, his sister received a text message from someone that evening and then told her parents she was going out for dinner with a friend. She then texted her father at 11 p.m. to tell him that she would return home the next morning but hasn’t been heard from since.

Investigators say that the last known sighting of Li was in the Richmond Hill area at around 7 p.m. on June 12. Hu said that police have informed him that the location where Li was spotted was a Chinese restaurant.

“She just said she was going out with a friend. We don’t know what friend,” Hu told CTV News Toronto on Wednesday.

In a press release issued Wednesday, police said that they are “growing increasingly concerned” for Li’s well-being and now consider her disappearance to be suspicious.

Police also said that they are seeking the public’s assistance in identifying a woman who was captured by a surveillance camera and “may have information” about Li’s disappearance.

“We have had updates in terms of new information that has caused our homicide unit to take over the investigation. In some cases it does fall under the homicide unit’s mandate to investigate missing persons where there are suspicious circumstances but I can’t specifically disclose those circumstances,” Const. Laura Nicolle told CTV News Toronto on Wednesday.

While homicide detectives are investigating, Nicolle said that police are still “optimistic” that Li is alive.

Li is described as Asian, five-foot-two and 120 pounds, with brown eyes and black hair.

Anyone with information is asked to contact the York Regional Homicide Unit at 866-876-5423 ext. 7865., or call Crime Stoppers at 800-222-TIPS.