An immigrants' rights organization has filed a class-action lawsuit against the U.S. Department of Homeland Security for issuing detaining orders against individuals in custody while their immigration status is being investigated.

The Heartland Alliance's National Immigrant Justice Center used the examples of two Latinos - one a U.S. citizen and the other a permanent resident - to question the constitutionality of applying what are known as immigration detainers.

Jose Jimenez Moreno, 34, was arrested last March in Rockford, Illinois, for narcotics possession and was sent to a Winnebago County jail under a DHS detainer.

As a U.S. citizen, he is not subject to deportation.

For her part, Maria Jose Lopez, mother of three U.S.-born children, was sent to a federal correctional lockup in Tallahassee, Florida, where she has been held since February on an immigration detainer.

"The conviction that led to Ms. Lopez's incarceration is not grounds for deportation under U.S. immigration law," according to NIJC.

Neither Jimenez nor Lopez has been contacted by DHS.

In the lawsit filed last Friday with a federal district court in Chicago, NIJC attorneys question DHS authority to order federal, state and local police agencies to keep individuals in custody without probable cause.

"Additionally," the suit maintains, "DHS's use of detainers violates the 10th Amendment because it requires state and local governments to implement federal law."

People subject to detainers are not informed of the existence of the order or given a chance to dispute it, NIJC said.

"DHS detainers deprive thousands of men and women of basic constitutional due process rights," NIJC Executive Director Mary Meg McCarthy said in a statement.

"This expansive use of detainers harms U.S. citizens, lawful permanent residents, families, and communities, and betrays American ideals of fairness and justice," she said.

The plaintiffs charge that detainers have become an important police tool of the Obama administration to increase the number of deportations among undocumented immigrants.

They mention official statistics, according to which DHS issued 270,988 detainers during the fiscal year 2009, and 201,778 in the first 11 months of fiscal year 2010.

The suit names as defendants Homeland Security Secretary Janet Napolitano, Immigration and Customs Enforcement Director John Morton and Ricardo Wong, ICE regional director en Illinois, Indiana, Wisconsin, Missouri, Kentucky and Kansas.

Besides representing Jimenez and Lopez, the attorneys include "individuals who are suffering or will suffer violations to their constitutional rights as a result of the DHS detainers."

Claudia Valenzuela, one of the NIJC attorneys, told Efe that the judge assigned to the case will soon hold a hearing of the parties involved to weigh their arguments and decide whether to accept the suit as a class action.