Toronto Crime Stoppers is teaming up with International Crime Stoppers in an attempt to broaden the hunt for clues about the disappearance of Toronto teenager Miriam Makhniashvili.

The crime prevention group is distributing security camera footage of the 17-year-old, a YouTube appeal, stills of Mariam on Facebook and messages on Twitter to its partners on five continents, it said Tuesday.

They have three videos in English and three in the Georgian language.

Mariam and her brother George emigrated here from the Republic of Georgia in June to be reunited with her parents, who had been working in Los Angeles for five years.

On Sept. 14, Mariam and George set out from their 20 Shallmar Blvd. apartment building home to Forest Hills Collegiate Institute, located southeast at 730 Eglinton Ave. W.

George has told police that he and Mariam walked to school together. He went in the rear entrance, while she told him she would go in the front door, which was closer to her first-period class.

That is where her trail ends.

Const. Tony Vella, a spokesperson for the Toronto Police Service, told ctvtoronto.ca on Tuesday that the Makhniashvili case appears to be "one of the rarest of investigations."

This is still considered a Level 3 search, which is the highest priority the Toronto police can assign. There are 10 detectives working on sorting through the various tips that are coming in, he said.

"We're hoping to get a tip from the member of the public or someone to assist us," he said, adding that officers have exhausted the groundwork in the area where she was last seen.

Police believe Mariam returned home from a dragon-boat-race outing with George on Sunday, Sept. 13, but after that, they have no independent supporting evidence of her whereabouts, Vella said.

Tips continue to role in, but it takes time to validate them, he said.

Right now, there is no evidence to support a finding of foul play -- and no evidence to support a finding that Mariam just walked off on her own, Vella said.

In normal missing-person cases, investigators have a clear direction to follow within hours, he said. "But in this case, for over two weeks now, there's no direction in the investigation except that she's gone missing."

Her family has said Mariam was enjoying life in her new country. They describe her as a calm, shy and level-headed girl for whom running away would be highly out of character.

Police have been in contact with a friend of Mariam's in her homeland of Georgia, and that person has indicated it's strange Mariam hasn't tried to make contact with anyone.

"It's strange that if she's alive and out there, she wouldn't contact someone who would then contact police," Vella said, adding, "Nobody just vanishes. It's just going to take a matter of time."

Vella also noted this: "A lot of people are speculating, but we're hoping to get some evidence."

Anyone with information is asked to contact police at 416-808-5300, Crime Stoppers anonymously at 416-222-TIPS (8477), online at www.222tips.com, or text TOR and a message to CRIMES (274637).