Afederal judge is now requiring the government to provide an explanation as to why data on missing separated parents was not disclosed at an earlier date.

The data includes phone numbers and addresses that could help locate some of the more than 600 parents who have still not been found after they were separated from their children at the southern U.S. Border between 2017 and 2018. The data could help with efforts to reunite the parents with their children.

At a Friday status hearing, Judge Dana Sabraw of the Southern District of California asked lawyers representing the government to provide an official declaration to explain what kept officials from providing the information earlier.

“The fact that they’ve been sitting on these phone numbers has really been outrageous,” said Lee Gelernt, deputy director of the ACLU Immigrants’ Rights Project and lead attorney representing the separated children, at the Friday hearing. “We strongly urge the government to continue searching for more information…they know their data better.

The government shared the previously undisclosed data with a steering committee charged with locating the parents on Nov. 25, according to court documents. ADVERTISING

The new data comes from the Department of Justice’s Executive Office for Immigration Review (EOIR), containing phone numbers and other information that was not previously shared with lawyers and nonprofit organizations who make up the steering committee appointed by the judge to locate the families who were separated as part of the Trump Administration’s Zero Tolerance policy.

“Because the information was provided on the Wednesday before Thanksgiving, the Committee has not yet had time to determine the full scope or usefulness of this new information,” reads a joint status report filed in court on Wednesday.

The parents of 628 children have not yet been located by the steering committee, the status report says. (A previous court filing from October reported 545 children’s parents had yet to be located, but on Nov. 9, NBC News obtained an email containing information that the number increased to 666). 

Of those 628, parents of 333 are believed to have been deported, and the parents of approximately 295 children are believed to be in the U.S. The steering committee adds that though the parents have not yet been located, another family member has been reached for 168 of the 628 children. An initial court document filed on Wednesday stated 295 parents were believed to have been deported, and approximately 333 were believed to be in the U.S., but lawyers representing the children clarified during the Friday court hearing that the numbers were an error, and should actually be reversed. This article has been updated to reflect the correction.

Lawyers representing the government said officials were not intentionally withholding information, but that because EOIR is not involved in the investigation and search for the missing parents. According to the government’s lawyers, it took a brainstorm by government officials before realizing data kept by EOIR could be useful.

“We are hopeful that [the data] will be helpful going forward,” said Sarah Fabian, a lawyer for the government. “We don’t believe that this was a neglectful or a nefarious attempt.”

Several organizations involved in the search for parents of the separated children have criticized the government for not sharing the information sooner.

“The Trump Admin purposely withheld vital information delaying the process of reuniting children separated from their parents. It’s cruel & a violation of human rights that our gov’t unduly prolonged these children’s pain & suffering,” shared Kids In Need of Defense (KIND), an organization which provides legal representation and support for the children who remain in the U.S., in a Thursday tweet.

Justice in Motion, which works with volunteers in Central America to help locate the parents who are believed to have been deported there, called for President-Elect Joe Biden to return the deported parents to the U.S. and grant the families a legal status in a Wednesday Tweet.

Biden has promised to dedicate a task force on day one of his Administration to help locate the remaining parents and reunite them with their children.