The American Civil Liberties Union is accusing the federal government of denying undocumented immigrants due process rights while they’re detained, in violation of constitutional protections.

In a 113-page legal briefing filed Thursday in federal court, the civil liberties group’s Massachusetts and New Hampshire affiliates allege the U.S. Department of Justice, as well as numerous prison superintendents and the director of Immigration and Customs Enforcement, are unnecessarily jailing undocumented people while their cases work their way through the immigration courts.

The class action suit accuses federal immigration authorities of systematically failing to prove that a detained immigrant is a danger to others or a flight risk, and is instead requiring those immigrants to offer their own evidence that they are good candidates for release.

As a result, the ACLU says that hundreds of people who are allegedly in the country illegally are unnecessarily detained in Massachusetts and New Hampshire, including in the Strafford County Department of Corrections in Dover.

“This lawsuit raises an alarming issue where due process is being denied to those that have the most difficulty accessing counsel and navigating the American immigration system,” writes ACLU legal fellow SangYoeb Kim in a statement. “It is happening all too often, and today we’re suing to stop this terrible practice.”

The suit names three plaintiffs, including Jacky Celicourt, a Haitian immigrant arrested by ICE in January as he exited a Nashua courtroom, where he faced charges of stealing a $5.99 pair of earbuds. Celicourt, who fled Haiti fearing political violence, remains held in custody. The ACLU alleges he is being denied “an adequate detention hearing.”

Another named plaintiff, Florentin Avila Lucas, who the ACLU describes as a dairy worker in New Hampshire, was detained in March. A third man, Gilberto Pereira-Brito of Brockton, Mass., was also detained in March after ICE arrived at his home.

This report comes from the New England News Collaborative: eight public media companies, including The Public's Radio, coming together to tell the story of a changing region, with support from the Corporation for Public Broadcasting.