A group working to end U.S. immigration detention has named an Alabama jail as the worst county-run immigration detention facility in the country for reports of sexual assault.

Community Initiatives for Visiting Immigrants in Confinement (CIVIC), a San Francisco-based advocacy group, today filed a federal civil rights complaint with the Department of Homeland Security's Office of Civil Rights and Civil Liberties.

The complaint alleges sexual abuse, assault and harassment reports at U.S. immigration detention facilities, along with a lack of adequate government investigation into those cases.

In the complaint, the group lists the Etowah County Detention Center sixth in the country for sexual and physical assault complaints, behind five privately-run detention facilities in Louisiana, Texas, California and Washington State.

According to CIVIC, which said it bases its figures on records from Immigration and Customs Enforcement between October 2012 and March 2016, there were 14 calls to ICE's Detention Reporting and Information Line (DRIL) reporting sexual and physical assault, or one call for every 20 people in the jail.

Christina Fialho, an attorney and the co-executive director of CIVIC, said the number of reports around the country are a sign that Congress should begin a comprehensive investigation of sexual assault in the U.S. immigration detention system.

"The Etowah County Detention Center is one of the worst immigration detention facilities in the country," Failho said. "We have documented physical abuse and medical neglect in immigration detention at the Etowah County Detention Center for years. Now data from DHS shows us that there are more sexual assault complaints at Etowah than at any other county-run immigration detention facility nationwide. It is time for ICE to end its contact with Etowah County."

Etowah County Sheriff Todd Entrekin said CIVIC, in its letter, stated that the number of calls to DRIL did not square with the much larger number of total complaints logged.

"Any complaint of sexual assault or calls made to the PREA hotline, inside the Etowah County Detention Center, have been investigated and all have been unfounded," Entrekin said. "Anyone can take statistics and construe them. Even CIVIC makes note that it is difficult to draw any conclusions from the released data."

ICE is the agency that oversees the 211 adult and family immigration detention facilities around the country. Etowah County holds between 700 to 750 total inmates on any given day, and 315 are immigration detainees.

The jail has been the scene of several protests over the last four years by immigration advocacy groups, alleging lack of medical care, abuse and civil rights violations there among detainees, leading to a "Shut Down Etowah" campaign.

In the group's 14-page complaint, it calls on Congress to convene a bi-partisan group to investigate the reports or close all immigration facilities. CIVIC also calls for ICE to institute a zero-tolerance policy for sexual assaults along with mandatory staff training; offer visas to victims of sexual abuse, and mandatory disclosure of any sexual abuse reports in ICE or DHS facilities.