Tibor Baranyai, 44, left his native Hungary on a promise of a high-paying job in 2009, but once he landed at Pearson Airport in Toronto, he was taken to Windsor, Ont. where he was forced into hard labour.
He said he was locked in a basement with no light and no furniture except for a single mattress on the floor, until his escape in 2010.
Baranyai's testimony against his captors helped convict those caught in what the RCMP called the biggest human-trafficking bust in Canadian history.
The ring was part of one of Hungary's largest organized crime families, and Baranyai cannot return to Hungary, he said, out of fear that the traffickers' friends will retaliate.
Baranyai was granted refugee status in Canada, but his wife Ildiko Dellamario and her daughter Ildiko Nagy were denied the right to stay.
They too are Hungarians, and Dellamario sought refugee status in Canada because she claimed she had been threatened by customers of the bank where she had worked in Budapest.
After coming to Canada, Dellamario and her daughter settled in Montreal, where the mother worked as a cook at a Hungarian restaurant.
Baranyai met her through an internet dating site while living in Ontario, then moved to Montreal where he married her.
Now Baranyai and his family fear his involvement with bringing down the human traffickers could imperil his wife and stepdaughter upon their return to Budapest.
"It still exists, this Mafia in Hungary," said Nagy. "We really believe they will find us, since we cannot hide. We don't want to hide, but we could not, anyway. It is a small country. they would find us, and they would hurt us...or worse."
The mother and daughter were to be on a flight bound for Budapest early Friday evening. A spokesperson for the Canada Border Services Agency said Friday night that for operational and safety reasons, the CBSA would not confirm their departure.