The American Civil Liberties Union (ACLU) is claiming that Immigration and Customs Enforcement (ICE) for more than a month purposefully withheld hundreds of migrant parents' contact information from their lawyers.

The ACLU made the allegation to HuffPost this week after it said the government finally gave it phone numbers for more than 400 parents who had been separated from their children due to President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE's "zero tolerance" immigration policy.

ADVERTISEMENT

“The numbers have been [in the children’s files] for a while, and we should have had them for a while,” Lee Gelernt, the lead lawyer for the ACLU's lawsuit against ICE, told HuffPost. “Every day that we didn’t get them is another day we didn’t track parents down [and] weeks and months, potentially, where kids are potentially by themselves.”

Gelernt also said that he believes ICE had access to the phone numbers before the court-ordered family reunification deadline on July 26. He added that the government eventually handed over the phone numbers on Aug. 7, which was about a week after it was asked to do so by the ACLU and a judge.

“I don’t think the government felt any obligation to take any initiative,” Gelernt said, adding that the separation crisis was created by the government. “It doesn’t seem like if you’re sitting on the phone numbers, that we [should] have to tell you, ‘Yes, we want them.’ ”

ICE did not immediately return a request for comment from The Hill.

The news report from HuffPost came the same day that ICE said in a court filing that the government has more than 300 children in custody whose parents are outside the U.S.

About 1,500 migrant children have been reunited with their families since the Trump administration in June halted the controversial process of separating children from their parents.

The administration continues to face pressure from groups like the ACLU and lawmakers on how it will reunite every family that was separated.