The migrant parents of over 600 children have yet to be accounted for, and now it’s been revealed that the Trump administration has been sitting on valuable information that could lead to their reunion.

A new report found the Trump administration withheld the addresses and phone numbers of separated families, thereby making it harder to reunite families because of the omission.

“These families belong together here in the United States — and a human rights commission should investigate what happened, even refer prosecutions,” Rep. Joaquin Castro and Hispanic Caucus Chair wrote in response to the report by NBC.

Legal advocates say that after many months of pleas to obtain more information that could help find migrant families separated at the U.S. border in 2017 and 2018, the government finally handed over new data last week, just under 50 days before the end of Trump’s presidency. 

Back in October, federally-appointed judges revealed they have been able to track down the parents of at least 545 children, adding that about  two-thirds of their parents have been deported back to Central America, forced to leave their children behind.

These children, whose parents brought them across the border are now subject to damaging psychological effects, and parents have been forced to navigate the prolonged loss of a child — either from thousands of miles away in their countries of origin or within detention centers.

With many, there is a real danger hundreds of children will never see their families again.

“We've finally received new data from the Trump administration that will hopefully help us find the families separated by their cruel family separation practice,” the ACLU wrote on Twitter, adding that they withheld the vital information for over a year. 

NBC updated the total number of children in November — to over 660— and again on Dec. 2, with the filing saying some families have been identified since then, bringing the new total to 628.

With the new data, lawyers told NBC the number could be reduced further.

President-elect Joe Biden has said he will set up a task force to find and reunite separated families, but his transition team has yet to give parents who have been deported the option to come to the U.S. for a reunion.