Rep. Joaquin Castro (D-Texas) revealed Friday night that Customs and Border Protection (CBP)  Commissioner Kevin McAleenan knew about a 7-year-old migrant girl’s death while in its custody before his congressional testimony earlier this week but failed to mention it.

Speaking on MSNBC, Castro recalled a conversation he had with McAleenan in which he admitted he knew of Jakelin Caal Maquin’s death before appearing in front of the Senate Judiciary Committee.

{mosads}“I was very disturbed by that answer,” Castro said, noting that if someone dies in CBP custody, the agency is supposed to notify Congress within 24 hours, which the agency did not do.

“Now his argument was that he had not gotten a privacy release from the family, and that also, he didn’t want to politicize the death,” he added, arguing that McAleenan could have described her as a 7-year-old girl and not identified her. “So this is going to be a very serious problem for him and an issue that the next Congress will look into.” 

The Department of Homeland Security’s inspector general announced Friday it would investigate the death and publicly release a report at the inquiry’s conclusion.

Caal’s death from dehydration and shock was first reported Thursday. She had illegally crossed the border last week with her father and a group of other migrants and was taken into custody by Border Patrol in New Mexico. 

She reportedly began having seizures eight hours after being detained, and emergency responders found she “reportedly had not eaten or consumed water for several days.”

Caal was flown to a hospital in El Paso, Texas, but died less than 24 hours later. NBC News reported Friday that the girl was first treated an hour and a half after showing symptoms. 

“Unfortunately, despite our best efforts and the best efforts of the medical team treating the child, we were unable to stop this tragedy from occurring,” a DHS spokesperson said in a statement to The Hill. “Border Patrol agents took every possible step to save the child’s life under the most trying of circumstances. As fathers and mothers, brothers and sisters, we empathize with the loss of any child.” 

As arrests at the border have skyrocketed this year, CBP and other agencies have been detaining migrants in detention facilities that McAleenan has said were built “to handle mostly male single adults in custody, not families and children.”