Story highlights The ACLU says three immigrant women were sexually assaulted in ICE custody

A class-action lawsuit has been filed on their behalf, the ACLU says

"We believe these complaints are just the tip of the iceberg," an ACLU lawyer says

ICE says all abuse allegations are investigated and the agency has a "zero tolerance" policy

A class-action lawsuit has been filed on behalf of three immigrant women who were allegedly sexually assaulted while in the custody of Immigration and Customs Enforcement in Texas, the American Civil Liberties Union said this week.

The ACLU, citing documents it said it had obtained through the Freedom of Information Act, said in a news release that there have been nearly 200 allegations of sexual abuse of immigration detainees jailed at detention facilities across the United States since 2007.

The ACLU release did not give dates of any of the alleged assaults, including those involving the three women who are plaintiffs in the class-action suit. The plaintiffs were identified only as Sarah Doe, Kimberly Doe and Raquel Doe "to protect them from further harm," the ACLU said.

The alleged attacks occurred while the plaintiffs were being transported from the T. Don Hutto Family Residential Center in Taylor, Texas, to the airport or bus station in nearby Austin, the ACLU said.

Its release did not say where the class-action suit was filed Wednesday, but it said defendants include three ICE officials; Williamson County, Texas, where the Hutto facility is; the Corrections Corporation of America (CCA), a private prison company that manages the Hutto facility; the former facility administrator for Hutto; and a guard at the facility.

The lawsuit alleges that ICE along with Williamson County and the Corrections Corporation of America were "deliberately indifferent and willfully blind to the fact that (the guard named as a defendant) and other employees regularly violated the rule that detainees are not be transported without another escort officer of the same gender present," the ACLU said.

ICE did not comment specifically on the ACLU's announcement of the lawsuit, but an agency spokeswoman said ICE "maintains a strict zero tolerance policy for any kind of abusive or inappropriate behavior and requires all contractors working with the agency to adhere to this policy."

ICE Public Affairs Officer Gillian Christensen added that the agency requires regular criminal backgrounds checks for its workforce.

"The (Department of Homeland Security) Office of the Inspector General and ICE's Office of Professional Responsibility investigate ALL allegations of sexual abuse or misconduct and the agency takes appropriate action -- whether it is pursuing criminal charges or administrative action -- when those allegations are substantiated," Christensen said in the ICE statement.

The Corrections Corporation of America did not immediately respond to requests for comment on the ACLU announcement.

The ACLU said it was basing its claim that there have been 185 allegations of sexual abuse in federal detention centers against female immigration detainees on various federal documents.

The documents -- obtained from the Department of Homeland Security's Office of Inspector General, Office of Civil Rights and Civil Liberties and ICE, according to the ACLU -- showed that Texas had more alleged abuse cases, 56, than any other state, the organization's news release said.

"While the information gleaned from the documents likely does not represent the full scope of the problem given that sexual abuse is notoriously underreported, the documents nonetheless make clear that the sexual abuse of immigration detainees is not an isolated problem limited to a few rogue facilities or to a handful of bad-apple government contractors who staff some of the nation's immigration jails," the ACLU said.

"Unfortunately, we believe these complaints are just the tip of the iceberg," said Mark Whitburn, senior staff attorney for the ACLU of Texas.