Update 6/20 10:00 a.m.: This story has been updated to reflect a comment from a Customs and Border Protection spokesperson.

A 10-year-old girl with Down syndrome was separated from her parents at the U.S. Customs and Border Protection facility in McAllen, Texas, according to the Mexican government.

In a press conference about the U.S. family-separation policy Tuesday, Mexican Foreign Minister Luis Videgaray expressed his concern on behalf of the 25 known Mexican nationals who have been affected by the Trump administration’s “zero tolerance” immigration policy, which is causing immigrant children to be separated from their parents at the border. Videgaray called the separation policy “cruel and inhumane.” He paid particular attention to the case of a 10-year-old girl, a Mexican citizen, who was separated from her mother at the border.

The girl has Down syndrome and, according to Videgaray, she was taken from her mother at the now-infamous Customs and Border Protection processing center in McAllen, where kids are being held in cage-like enclosures.

“I refer now to a particularly painful case that is the case of a 10-year-old girl who was separated with her brother, also 10, who is in a shelter in McAllen,” Videgaray said. “She's a Mexican girl who has Down syndrome and who last week was separated from her mother, who was sent to a detention center in Brownsville,” another part of Texas.

A CBP spokesperson confirmed to VICE News on Wednesday that the 10-year-old had been separated from her parents — but not as a result of the "zero tolerance" policy, under which her mother would be criminally prosecuted and detained in federal jail. Instead, she's being held as a witness, according to the spokesperson.

"The mother was not prosecuted, but is instead being held as a material witness to support the prosecution of the smuggler, which precipitated the separation of the two other children, both Mexican citizens," the spokesperson said. "This smuggler has a criminal history including a flight, escape, aiding and abetting that making it important that we prosecute."

DHS wouldn't elaborate how its family separation policies are applied to families in which a child has a disability.

The mother, who admitted to being undocumented, was driving in a vehicle with a U.S. citizen and her five children, three of whom are U.S. citizens and released to the care of their aunt, according to the spokesperson. The other two children, including the 10-year-old with Down syndrome, are Mexican citizens and remain in the care of Health and Human Services' Office of Refugee Resettlement.

The girl’s father is a U.S. resident who is currently at the Mexican consulate in McAllen, according to Videgaray. He’s filling out paperwork that would allow the girl to be released from U.S. custody and be reunited with her family.

“We have notified the U.S. authorities at the highest level of this case in particular,” Videgaray said.

Agent Carlos Ruiz, a U.S. Customs and Border Protection public affairs officer at the Rio Grande Valley sector in Texas, the regional office that oversees the McAllen facility, told VICE News on Tuesday that he was not aware of any case involving a girl with Down syndrome at the McAllen detention center.