The cases against all eight suspects, originally from Poland, ended Friday, allowing reporting restrictions to be lifted and details of their trials to be published.
Prosecutors say the victims, who were from Poland, were forced to work for barely any money while the organizers of the operation earned several million dollars. They say the human trafficking ring lured homeless people, former convicts and alcoholics from Poland to Britain with promises of well paid work but instead forced them to live in squalid conditions, paying some less than $1 a day.
Victims described going to food banks to try to find enough to eat and of being threatened or assaulted if they complained.
Jurors in two separate trials in Birmingham heard the accounts of more than 90 victims.
All eight suspects, part of a criminal gang led by the Brzezinsky family, were convicted of modern slavery offenses. Seven of them were also convicted of money laundering.
They received sentences ranging from 4½ to 11 years.
Judge Mary Stacey said at the end of the first trial earlier this year that the conspiracy, which ran from 2012 to 2017, was the “most ambitious, extensive and prolific” modern-day slavery network ever uncovered.
The operation was discovered by the anti-slavery British charity Hope for Justice. The group said it alerted police after victims made contact through its outreach efforts.