TAHLEQUAH, Okla. — A class-action lawsuit filed against an Oklahoma drug rehabilitation program alleges participants were forced to perform thousands of hours of free labor for businesses and individuals in Oklahoma and Arkansas.

The ACLU of Oklahoma filed the suit Wednesday on behalf of seven people. It alleges the Drug and Alcohol Recovery Program “created a pipeline for forced labor” and human trafficking at its facilities in Tahlequah, Oklahoma, and Decatur, Arkansas.

Oklahoma district courts have ordered drug and alcohol offenders to participate in the program as an alternative to incarceration. The lawsuit says participants work under threat of imprisonment and live in squalor.

The lawsuit is among several filed after nonprofit news outlet Reveal from The Center for Investigative Reporting published a story exposing the questionable practices of some court-ordered diversion programs.