The owner of a local pizza chain in Boston was found guilty Friday of forced labor after prosecutors said he physically abused and threatened to report six undocumented workers to immigration authorities.

Stavros Steve Papantoniadis, 48, of Westwood, the owner of three Stashs Pizza restaurants in Boston, was convicted of three counts of forced labor and three counts of attempted forced labor, the U.S. attorneys office in Massachusetts announced.

Papantoniadis was initially arrested in March 2023 following reports that he had been targeting undocumented employees for about 14 years, NBC affiliate WBTS-TV in Boston reported at the time.