Thousands of migrant children placed in US custody between 2014 and 2018 were reportedly sexually abused in government-administered shelters, according to documents first published by Axios.

Many of the allegations were made against fellow migrant children — but at least 178 were made against adult staff members at the facilities.

Rep. Ted Deutch, a Florida Democrat, questioned Trump administration officials about the allegations during a House Judiciary Committee hearing on Tuesday.

Deutch asked whether the risk of sexual abuse was discussed when family separations were taking place en masse last spring.

"In every conversation that we had about separation, we opposed separation," a top Health and Human Services official responded.

Thousands of migrant children in US custody reported sexual abuse allegations while they lived in government-administered shelters, new documents show.

Rep. Ted Deutch's office gave Axios a copy of the documents, published Tuesday.

They show that between October 2014 and July 2018, the Department of Health and Human Services (HHS) received 4,556 complaints of sexual abuse, and the Department of Justice received 1,303 complaints.

The vast majority of the 1,303 abuse allegations made to DOJ accused fellow migrant children of abuse. But the allegations also included 178 against adult staff members at the facilities, and 19 against adult non-staff members, according to Axios.

The children were placed in shelters after arriving in the country illegally. During the time in question, tens of thousands of migrant children arrived in the US and stayed in government-administered shelters.

HHS told INSIDER in a statement that all allegations of abuse, sexual abuse, or neglect are "taken seriously" and investigated.

"The safety of minors is our top concern when administering our unaccompanied alien children program," spokeswoman Caitlin Oakley said. "These are vulnerable children in difficult circumstances, and ORR fully understands its responsibility to ensure that each child is treated with the utmost care."

Read more: Thousands more children were separated from their parents at the border than were previously known, inspector general reveals in bombshell report

The documents outline disturbing allegations

Occupants at Casa Padre, an immigrant shelter for unaccompanied minors, in Brownsville, Texas, U.S., are seen in this photo provided by the U.S. Department of Health and Human Services, June 14, 2018. Health and Human Services handout via Reuters

Nine pages of documents that Axios obtained, from the Office of Refugee Resettlement, which is part of HHS, details dozens of allegations from 2014 to 2016, along with notes on whether staff members were suspended or terminated, and whether the shelters in question remained open. It also lists incidents from 2017 and 2018.

The documents reveal a number of disturbing allegations, including one minor who in 2016 reported that he had sex with a staff member on four occasions. His allegation was deemed "unfounded" and the investigation was suspended.

In another 2016 instance recorded in the documents, a migrant child reported that a staff member grabbed his crotch and squeezed — while the child was physically restrained. That complaint was not investigated and the staff member was moved to another housing unit, the documents said.

Another allegation in 2016 said a worker sent a migrant child explicit photos of herself after the child had been released from the shelter. The alleged incident was investigated by the Office of the Inspector General and the staff member was terminated, according to the document.

'It was our obligation ... to help keep these kids safe'

—Rep. Ted Deutch (@RepTedDeutch) February 26, 2019

During a House Judiciary Committee hearing Tuesday morning, Deutch, a Florida Democrat, lambasted a panel of Trump administration officials about the sexual abuse allegations — hundreds of which occurred during 2017 and 2018.

"The details of these sexual abuse allegations are shocking," Deutch said. "It was our obligation — the administration's obligation — to help keep these kids safe. … Mr. Chairman, we failed."

Deutch then asked whether the risk of sexual abuse was discussed during the height of the Trump administration's "zero tolerance" policy last spring, which resulted in the separation of thousands of migrant children who were placed in the government shelter system.

"In every conversation that we had about separation, we opposed separation," Commander Jonathan White of the Public Health Service Commissioned Corps responded.

When asked by Rep. Matt Gaetz, a Florida Republican, whether the children were more susceptible to sexual abuse in US custody or during their journeys to the US, White said the journey was more dangerous for them, but "that's not the point."

"We're committed to keeping an environment safe for children. We don't set ourselves a standard of just doing better than smugglers and traffickers," White said.