An undocumented construction worker who was arrested by ICE after filing a worker's compensation claim two years ago was, according to a complaint filed by the U.S. Department of Labor Wednesday in Boston's federal court, unlawfully retaliated against by his Boston-based employer.

The DOL further asserted a Boston police sergeant was involved in the employee's arrest by ICE.

Two months after reporting an injury he incurred in March 2017, Jose Martin Paz Flores, who was in the country without documentation at the time, was arrested by ICE after leaving a meeting at the Tara Construction offices. Attorneys for Paz feared the timing of the arrest suggested cooperation between the employer and ICE.

(Paz has since obtained work authorization. He has been ordered to regularly check in with ICE as he pursues legal status in the U.S.)

The law states immigrants in the country illegally are almost always entitled to the same workers' comp benefits as U.S. citizens.

The DOL's complaint described a series of events, triggered by Paz's workplace accident, that ultimately led to his arrest by ICE.

At the time Paz fell from a work ladder, Tara Construction did not have workers' compensation insurance after the company's policy had been cancelled due to non-payment. Occupational Safety and Health Administration (OSHA), the complaint stated, was brought in to investigate the fall.

According to the complaint, Pedro Pirez, who runs Tara Construction, allegedly initiated the law enforcement investigation of Paz in 2017.

Pirez contacted Boston Police Detective Juan Seoane shortly after Paz reported his injury, the complaint said, asking the detective to look into Paz's identity and providing the detective with identifying information for Paz. Pirez told OSHA investigators that he was confused by Paz's multiple middle and last names, which is why he reached out to Seoane.

Seoane then contacted Boston Police Sergeant Detective Gregory Gallagher, who was on a "joint ICE/Boston Police Department task force," the documents alleged. The nature of this task force is unclear. Boston police were unable to respond to request for comments by deadline.

The office of Boston Mayor Marty Walsh, who has repeatedly pledged to preserve the city's "sanctuary" status, referred questions about the task force to the Boston Police Department.

The complaint further laid out a case of collaboration between Boston police and ICE. Gallagher and Pirez communicated directly via text message to confirm when Paz would be at the construction company's offices, the documents stated. Pirez requested that Paz come to the offices on May 10, 2017, to receive a check intended to help Pirez with expenses while he was unable to work. Just after Paz left the meeting, his car was stopped by law enforcement, the court documents stated, and he was arrested in the presence of Gallagher and ICE officials. His young son was in the car at the time and witnessed the arrest.

The complaint stated the actions taken by Pirez and Tara Construction would "dissuade a reasonable worker from reporting an injury" and asked for, among other things, reimbursement to Paz of lost wages.

Diego Low, a coordinator at Metrowest Worker Center, a Boston-based advocacy group run by and for immigrant workers, said employers often leverage immigration status over employees weighing workers' compensation claims.

"It's a thread through so many of our conversations," he said.

Low praised the DOL's complaint and said it delivered a clear message: "A worker, regardless of status, is entitled to the protections of the law that other workers are entitled to."

Stacie Sobosik, Paz's workers' compensation attorney, said lawyers "always struggle with how to advise clients about reporting workplace injuries" if the client has concerns about their immigration status.

"Particularly in the last several years because of the political climate both nationally and locally," she said. "But this is an important step in the right direction. So, when clients ask us, 'Do I face any kind of immigration response for filing a workplace injury?', we can tell clients, 'Possibly. But if your employer retaliates against you, there will be repercussions.' "

Paz is due back in immigration court this year. Attorneys for Paz said he has options to halt the government's efforts to deport him to his native Honduras.

Editor's Note: In WBUR's previous coverage, we refer to the employee as Jose Flores. To keep consistency with Wednesday's court documents, we have written out the employee's full name and referred to him by his surname Paz on all subsequent references.