Toronto Police Chief Bill Blair says his investigators are stumped by the disappearance of teenager Mariam Makhniashvili, who vanished about three months ago.

Blair told CTV Toronto on Tuesday that his officers have run out of leads in their search for the 18-year-old.

"I think the effort that has been made reflects the concern that we have for her safety," he said. "But I also believe now that we have exhausted every investigative opportunity available to us and we're now hopeful that someone who knows something will come forward with that information."

There's no evidence of a "predicating event" such as a dispute, a threat to the girl or anything to even indicate her intentions the morning she disappeared, Blair said.

Makhniashvili walked to Forest Hill Collegiate Institute on the morning of Sept. 14 with her brother George, then told him she would be going in the front door as it was closer to her first-period class.

That is the last confirmed sighting of Mariam, who came to Toronto with George in June from the Republic of Georgia to reunite with their parents. They had been working in Los Angeles for the past five years.

A few witnesses claimed to have sighted her in Toronto in the aftermath of her disappearance.

However, the latest unconfirmed sightings came from Alberta, specifically the towns of Okotoks, Hinton and Grande Prairie, which are hundreds of kilometres apart. The sightings began Oct. 27 -- the day Mariam turned 18 -- in Okotoks, which is just south of Calgary, and the last one in the northwest city of Grande Prairie on Dec. 2.

A brief item on the U.S. show America's Most Wanted this past Saturday failed to generate any new leads.

In Toronto, the only physical evidence to surface has been Mariam's school backpack, which was found at 120 Eglinton Ave. E. back on Oct. 8. That location is a few kilometres east of Mariam's school. But police have said they don't know if Mariam left the bag there.

The extraordinary moves the police have taken to find Mariam have included face-to-face interviews with about 6,000 people in the neighbourhood surrounding her family's apartment at 20 Shallmar Blvd. In addition, they have asked people to allow them to look inside their homes.

In addition, they had officers at the Ingram transfer station looking for any evidence that someone, spooked by the police presence, may have tossed out. Garbage from the Bathurst Street and Eglinton Avenue West goes to the Ingram station.

Police interviewed nearly another 1,000 people at Mariam's school. Det. Sgt. Dan Nealon told CTV Toronto on Nov. 26 that to that point, the effort didn't generate any leads.

Among the other techniques police have tried:

  • helicopter searches of parks and ravines Mariam and her family were known to have frequented
  • holding public assemblies at high schools to appeal for information
  • seizing computers she may have used at some neighbourhood public libraries

Mariam is said to be shy, quiet and introverted. She has no other family in Canada and hasn't been in touch with friends or family in Georgia. Her passport is still at home.

Mariam is white, 5'3" with light brown, shoulder-length hair and brown eyes. She was last seen wearing black jeans with front and back pockets and buttons as well as a baby blue, long-sleeved V-neck shirt. She was wearing a waist-length blue jean jacket.

Anyone with information is asked to call Toronto police at 416-808-5300, or to call Crime Stoppers at 416-222-8477. Members of the public can also send in tips online at www.222tips.com, or they can text TOR and a message to CRIMES (274637).

With a report from CTV Toronto's Jim Junkin