It has been more than two years since the disappearance of Toronto high school student Mariam Makhniashvili and despite a massive international investigation, police say they are no closer to knowing what happened to her.

According to Mariam's mother, Lela Tabidze, the morning of Sept. 14, 2009 was like any other, with Mariam and her brother George rushing to get ready for school.

Forest Hill Collegiate was just two blocks away from the family's mid-town Toronto apartment. George went in one door and Mariam headed for another. That was the last time anyone saw her.

When 17-year-old Mariam didn't come home after school, her father, Vakhtang Makniashvili made an anguished call to 9-1-1. That call launched what is considered the largest missing person search in Toronto history – by air, on land and water.

Officers knocked on 6,000 doors. They searched the school, talked with students, and checked the alibis of all the known local sex offenders, all in hopes of finding one clue that would help crack the case.

Massive public appeals kept tips coming in. Three weeks into the investigation, Mariam's backpack was discovered.

"We thought our prayers were basically answered because it was going to give us some direction to go in," said Det.-Const. Jennifer Young. Everything in her backpack seemed intact, both her books and her lunch were there. But there was no DNA or any other tangible evidence. In the end, the backpack turned out to be just one more dead end.

Police hoped further clues to Mariam's disappearance might surface in their investigation into the family's past. Toronto police asked Interpol and police in the Republic of Georgia to conduct background checks on the family but they uncovered nothing unusual.

"This was an ordinary family that lived an ordinary life" said Young.

Leaving the homeland

Lela Tabidze and Vakhtang Makhniashvili were married in the Georgian capital, Tblisi in 1991, just months before the impoverished country declared independence from the Soviet Union. Civil unrest and food shortages meant life was a struggle.

By 2003 there was no work for Makhniashvili, who was a professional musician and part time lecturer at the university. Tabidze was working as a broadcaster but she and other employees soon found that there was no money for them to be paid.

When an opportunity at a graduate college in Claremont, Calif. Arose, Makhniashvili and Tabidze seized the moment, even though it meant making the nearly impossible decision to leave their children behind in Georgia.

Mariam and George stayed with Makhniashvili's mother Tsiana Aleksishvili, but Tabidze admits the decision was difficult.

After spending five years in California separated from the children Tabidze and Makhniashvili applied to come to Canada under the skilled workers immigration program. They were given permanent residence status and in June of 2009, the family was re-united in Toronto, a fresh start that collapsed just 90 days later when Mariam failed to turn up from school, never to be seen again.

Cracking under the stress

Eight months after Mariam's disappearance the family was at the centre of another police investigation. Vakhtang Makhniashvili attacked and stabbed a neighbor, Sean Ure, living in the apartment across the hall.

In an exclusive interview with W5, Ure described the terrifying encounter with Makhniashvili: "He was saying you took my daughter. He just kept repeating it and I was caught completely off guard," he said.

Ure says he didn't know Mariam at all and has no idea why Makhniashvili suspected he was involved in her disappearance.

Makhniashvili was arrested for the attack. At his bail hearing he received a mysterious offer of help. David and Delores Langer came forward with an offer to post the $50,000 bail for Makhniashvili, a total stranger.

So far the Langers have not explained what motivated them to post bail, although it has been revealed that they had been in contact with the Makhniashvili family via the Internet, using assumed names.

As a condition of his release, Vakhtang Makhniashvili was supposed to live with the Langer's but within weeks, the Langer's wanted nothing more to do with him and withdrew their bail. Shortly afterward, Makhniashvili stabbed the Langer's in a brutal assault on the doorstep of their east-end Toronto home.

Lela Tabidze cannot explain her husband's behavior.

"He's not and never has been a violent person before. Everything that's happening to him is because of the stress," she said.

Makhniashvili, who came to Canada, seeking a better life for his family, pleaded guilty and was convicted of three counts of aggravated assault. He will be sentenced December 8.

Toronto Police Det. Sgt. Dan Nealon, who is the lead investigator into Mariam's disappearance, told W5 her father's problems have been distracting for the public but not for the police. "We remain focused and try to find out what happened to Mariam," said Nealon.

But for now the police and Mariam's family remain mystified by her disappearance and hope and pray that someone will come forward with information that will solve the mystery of Mariam's disappearance.

"I can't believe there is no person who has not seen anything or knows anything. It is impossible," said Tabidze.

Anyone with information is asked to call the Toronto Police Service at 416-808-5300 or Crime Stoppers anonymously at 1-800-222-TIPS