The former owner of the Boston-area chain Stash’s Pizza has been convicted of forced labor following a nine-day trial in federal court in Boston.

“Today’s guilty verdict sends a powerful message to abusive employers that exploiting employees through fear and intimidation will never be tolerated,” said acting U.S. Attorney for Massachusetts Joshua Levy. “I hope that this verdict also alerts others who may be victims of exploitation and harm by employers, that the federal government will not sit idly by.”

The federal jury convicted Stavros “Steve” Papantoniadis, 48, of Westwood, of three counts each of forced labor and attempted forced labor — charges that carry a sentence of up to 20 years in prison each.

Papantoniadis was arrested in March of last year and has remained in custody ever since. Chief U.S. District Judge F. Dennis Saylor IV scheduled sentencing for Sept. 12.

The feds say that Papantoniadis used “violent physical abuse, threats of abuse,” and repeated threats to have employees deported if they didn’t follow his commands. He used these tactics on five men and one woman he employed.

“Stavros Papantoniadis instilled fear in his employees. He underpaid and threatened them, some with fear of arrest and many with physical abuse. Today, the jury saw the indignities his employees were subjected to and have found Papantoniadis guilty of forced labor violations,” said Michael J. Krol, Special Agent in Charge of Homeland Security Investigations in New England. “Everyone deserves to be treated with dignity and respect – especially those who place their trust in their employer. HSI is committed to ensuring those who violate forced labor laws are held accountable and brought to justice.”

This is a developing story.