Until then, the Department of Health and Human Services (HHS) "will provide care and seek placement for the child using its ordinary programs and procedures,” the filing states.

However, the government stated that officials have since been unable to locate the mother, so it is impossible to reunite them.

"The child was separated from her parent in 2015 when her parent was arrested on an outstanding warrant by the U.S," it reads.

According a court filing on Thursday, written by lawyers from the Department of Justice, the child was separated when its mother was arrested in 2015 on an outstanding warrant by the US Marshals Service. It also refers to the child with feminine pronouns.

"[One] child cannot be reunified at this time because the parent’s location has been unknown for more than a year ... and records show the parent and child might be U.S. citizens," the court filing states.

The first indication that they may be US citizens came in a court filing Tuesday, when the government explained why it would not meet the deadline to reunify more than 100 separated children by July 9.

Little is known about the identities of the mother and child — with government departments even giving conflicting information about the child's gender.

A child under the age of 5 remains detained by the federal government after being separated from their mother at the US-Mexico border more than a year ago, even though they may be US citizens, officials said.

It appears the government is still trying to figure out what's going on with one child whose parent may be a US citizen (in an earlier filing, the govt said the child may be a US citizen) — filing today says child was separated from her parent in 2015 when the parent was arrested https://t.co/sN85jbs4TU

ICE spokesperson Danielle Bennett provided BuzzFeed News with some further details about the circumstances of the mother being detained, and said the child was male.

The adult described in the court filing presented herself and her minor son, born in Mexico, at a U.S. port of entry on the Texas border on Nov. 25, 2015. She was remanded to USMS custody on an outstanding warrant.

Bennett said the mother was never in ICE custody, and referred inquires to the HHS, which is responsible for the detained minors



When asked if ICE could explain the discrepancy between the government's court filings describing the child as a girl and ICE saying it was a boy, Bennett said she could not and told BuzzFeed News to follow up with the Department of Justice, whose lawyers wrote the filing.

"Our records definitely indicate male child," she said.

The agency told BuzzFeed News that no information could be provided on specific cases because of privacy and security concerns.

The child is one of dozens of children under the age of 5 and under who had yet to be reunited with their parents despite a federal court order last month that mandated reunification.

During a conference call with reporters Thursday, Matthew Albence, the executive associate director of ICE and Enforcement and Removal Operations (ERO), said that he had no specific information on the case. However, he did say that there must have been some concern over the validity of the relationship between the parent and child, which would have triggered a separation even before the Trump administration's "zero tolerance" policy.

Fifty-seven of the 103 children covered by the court order have so far been reunited with their parents as of Thursday morning. And 22 of the 46 children who have not yet been reunified, were kept separated because of safety concerns regarding the adult, officials reported.

Eleven of those adults have criminal backgrounds, including smuggling, domestic violence, and an outstanding warrant for murder in Guatemala. Seven adults were determined not to be the parent through DNA matching or by their own admission. However, government officials could not say if the adults were another family relative, such as an uncle, and argued that they had still misrepresented themselves by initially presenting themselves as the actual parents.

Another parent allegedly abused their child and another allegedly intended for the child to be housed in the US in a home with a child sex offender.

The other 24 children had not been reunified with their family because of the circumstances of the adult.

Eleven adults are in custody of US Marshals Services or state jail for other offenses.



However, 12 parents were already deported back to their home country without their children. Albence said that they were given the option of reuniting with their children and being deported together, but had decided against that in order for the child to remain in the US.

"We're under no obligation for people to bring people who have no lawful status in this country back into this country for reunification," he said.

Clarification: The gender of the child is currently unknown because of conflicting records; a previous version of this article said the child is a girl based on court records. This article will be updated when the child's gender is confirmed.