A Boston police detective is the subject of an internal investigation over his role in the 2017 immigration arrest of an undocumented construction worker.

A U.S. Department of Labor (DOL) lawsuit filed earlier this year in Boston's federal court first outlined details regarding Detective Juan Seoane's involvement in the arrest of Jose Martin Paz Flores.

The complaint alleges that Pedro Pirez, who runs Boston-based Tara Construction, initiated a law enforcement investigation of Paz, who at the time did not have authorization to work in the U.S. Pirez did so, the lawsuit says, by contacting Detective Seoane shortly after Paz reported a workplace injury.

Tara Construction did not have workers' compensation insurance at the time Paz fell off a ladder at work. In a report obtained by WBUR and submitted earlier this month to the police department's Bureau of Investigative Services, Seoane states under the subject line "Tara Construction Information" that he was asked over a phone call to help verify the identity of an employee. He goes on to say that based on his research, he determined the employee "had an immigration hit."

At that point, Seoane says, he contacted Sergeant Detective Greg Gallagher. WBUR previously reported that Gallagher is the Boston Police Department's designated ICE liaison. Gallagher then, according to Seoane, worked with Pirez to coordinate Paz's arrest by ICE after Paz picked up a check at the company's office. These accounts are also laid out in the DOL suit.

City officials say Boston police, as part of its community policing efforts, encourages the public to contact officers that they are familiar with if they need support, to report a crime or to assist in an investigation.

According to the city officials, the interactions related to this specific case are being reviewed by Seoane's commanding officer, who has the discretion to discipline Seoane if it is found that he violated department protocols or policies. That review is ongoing.

Daniel Dwyer, an attorney for Tara Construction, said in a statement Friday afternoon that:

Tara Construction, Inc., is a good contractor and a fair employer. The Secretary’s misguided lawsuit occurs in a political climate favoring blame and strife over calm analysis. Pedro Pirez and Tara will defend themselves against the suit and trust that when facts are aired, the United States District Court will sort the matter out and produce a just result.

Boston Mayor Marty Walsh made it clear in an interview with WBUR that in accordance with the city's Trust Act, the only instances in which he encourages Boston police cooperation with ICE is when the individual in question is wanted on felony criminal charges. According to his attorneys, Paz has no criminal convictions.