The American Civil Liberties Union said the documents, obtained through a Freedom of Information Act request, show the alleged abuse occurred in nearly every state, but Texas has had more allegations "by far" than any other state.
"It is clear there is an urgent need for the government to recognize just how pervasive a problem the sexual abuse of immigration detainees is and take immediate steps to fix the problem and ensure that everyone in the government's care is protected," David Shapiro, staff attorney with the ACLU National Prison Project, said in the news release.
"The detainees in immigration detention are a particularly vulnerable population."
The ACLU revealed the findings from the documents as it announced a class-action lawsuit alleging three immigrant women were sexually assaulted while in custody of Immigration and Customs Enforcement in Texas.
The ACLU of Texas filed the lawsuit on behalf of women who were allegedly sexually assaulted by staff at the T. Don Hutto Family Residential Center in Taylor, Texas, "along with numerous others who experienced similar trauma," the news release said.
The Texas lawsuit, filed in U.S. District Court in Austin, names as defendants three ICE officials; Williamson County, Texas; Corrections Corp. of America, the private prison company that manages the Hutto facility; the former facility administrator for Hutto; and Donald Dunn, a guard who pleaded guilty in state court to three counts of official oppression and two counts of unlawful restraint based on his assaults of five women. Dunn also has been charged with four federal counts of criminal violation of civil rights.
The three women immigrants were allegedly assaulted while Dunn was transporting women from the Hutto facility to the airport or bus station in nearby Austin.
CNN reported ICE didn't comment on the lawsuit but a spokeswoman said it "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."