Spanish-language media and human rights activists are actively educating illegal immigrants on how to break the law, avoid immigration agents and remain in the country even after a judge has ordered them to be kicked out, a top Obama administration official testified to Congress on Tuesday.

Sometimes families shield the children by refusing to open the door to Immigration and Customs Enforcement (ICE) agents, and other times they move the children to other locations, breaking their agreement with the Obama administration to notify the government of the children’s whereabouts.

In as many as 75 percent of cases, the children are actively hidden from agents sent out to try to deport them, Thomas Homan, the head of deportation operations at ICE, told the Senate Judiciary Committee.

“Even though we’re out looking for them, it’s getting more difficult, based on everything I just told you, to actually apprehend these people and remove them,” he said.

Overall, only about 3 percent of the more than 125,000 unaccompanied alien children (UAC) who surged across the border in the last 30 months have been deported, as Mr. Homan and his agents struggle with the sheer size of the population and the difficulties in tracking them down.

The Department of Homeland Security last month began trying to target children and families for deportation, working about 1,800 leads. But only 121 were actually rounded up.

Mr. Homan said that’s because when they show up at the address where the children are supposed to be staying, usually the agents leave empty-handed.

“For the number of UACs we arrested since January, three times as many weren’t at the address they were supposed to be at, never were or weren’t there any longer. The Spanish media, Spanish newspapers, a lot of NGOs are educating these folks on how not to comply with law enforcement,” Mr. Homan said. “There’s been many situations where we’ve been at the residence, we know they’re there, but they won’t open the door. My officers don’t have the authority, of course, to go into that house.”