Baljit Johal, Mukesh Kumar and Balwinder Jackhu sued 2 Sisters Food Group Ltd after being dismissed from the firm's chicken factory in West Bromwich in November over the allegations, which they always denied.
They won their cases for unfair dismissal following a hearing at Birmingham Employment Tribunal yesterday, Birmingham Mail reported.
Compensation will be decided at another hearing in March.
The tribunal had previously heard claims that the nightshift at the West Bromwich factory was "run like a gang" by supervisor Johal, shift manager Kumar and trainer Jackhu.
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She said the men were in positions of trust and temporary workers "might reasonably believe they had the power to secure jobs for them".
But the three men all denied the allegations and claimed that union members were paid 600 pounds to make false statements about them after they refused to take part in strike action.
Tribunal judge David Dimbylow has now ruled the factory workers had been unfairly dismissed.
"The informants were not asked any testing questions, nor were the claimants' accounts of events put to them for comment," he said.