FILE PHOTO: Migrant children are led by staff in single file between tents at a detention facility next to the Mexican border in Tornillo, Texas June 18, 2018. REUTERS/Mike Blake/File Photo

WASHINGTON (Reuters) - The House Oversight Committee has scheduled a hearing next week on the separation and treatment of immigrant children and has launched an investigation into reports of offensive Facebook posts by border patrol officers, the panel said on Tuesday.

Representative Elijah Cummings, the committee’s Democratic chairman, said the panel had invited Acting Secretary Kevin McAleenan from the Department of Homeland Security and Acting Commissioner Mark Morgan from U.S. Customs and Border Protection to testify on July 12.

“The Trump administration’s actions at the southern border are grotesque and dehumanizing,” Cummings said. “There seems to be open contempt for the rule of law and for basic human decency.”

The panel said the hearing would look into reports that unaccompanied children, many of whom were separated from their families, are being held in overcrowded, filthy conditions. It will also examine reports that current and former Border Patrol agents have posted racist, sexist and xenophobic comments on Facebook.

“The committee needs to hear directly from the heads of these agencies as soon as possible in light of the almost daily reports of abuse and defiance,” Cummings said, urging the two acting agency heads to appear voluntarily to answer questions.

The announcement of the hearing came a day after Representative Alexandria Ocasio-Cortez visited the main border facility in El Paso with other members of the House Hispanic Caucus and charged that migrants were being subjected to psychological abuse and told to drink out of toilets.

The Border Patrol also came under fire on Monday after the non-profit news site ProPublica reported that offensive content had been posted on a private Facebook group for current and former CBP officers.

Posts included jokes about the deaths of migrants and sexually explicit comments referring to Ocasio-Cortez, the news outlet said.