Critics of the Biden administration’s border policies say the Department of Homeland Security, in an effort to conceal the true scope of the crisis from the American people, is refusing to release data on how many illegal migrants apprehended at the border are immediately released.

A former federal immigration judge, Andrew Arthur, now a resident scholar at the immigration hawkish Center for Immigration Studies, says that tens of thousands of asylum seekers arriving at the border are routinely being released into the United States pending hearings in immigration courts, but the Department of Homeland Security refuses to say how many.

“We know how many people the Border Patrol stops because they tell us every month,” Mr. Arthur tells the Sun. The agency charged with detaining migrants at the border, Immigration and Customs Enforcement, “tells us how many people they receive from the Border Patrol each month, too. What we don’t know is how many of those people ICE just turns around and releases every month.”

“The Biden administration is doing a very artful job of hiding that number,” Mr. Arthur says.

In July, the Border Patrol reported that more than 127,000 migrants were apprehended at the border for attempting to enter the country illegally. More than 67,000 of those people were immediately released into the United States on humanitarian grounds, and 52,000 were handed over to ICE officials for expulsion, detention, or release. Unfortunately, for border watchers like Mr. Arthur, what happened to those 50,000 people is anyone’s guess.

Immigration and Customs Enforcement did tally the number of people deemed ineligible for entry that it received during the month of July but does not — in the same data set — release details about what happened to them. ICE reports state that of the more than 45,000 people it took into custody during the month, none were released, and none were detained.

“That is a legal and factual impossibility,” Mr. Arthur says. “You either release them or detain them. There is no third option.”

Mr. Arthur insists that the Department of Homeland Security has that information readily available because it has released it as part of court proceedings in one of the several lawsuits filed by Republican attorneys general seeking to stop President Biden’s relaxation of immigration enforcement at the border.

“They have the ability to release that information but they refuse to do it now because they don’t want people to know how many people they are releasing,” he says. The Department of Homeland Security did not respond to a request for comment by late Tuesday.

The criticism by Mr. Arthur and some Republicans in Congress took on a fresh urgency Tuesday after reports surfaced that the FBI has lost track of about a dozen nationals from the central Asian nation of Uzbekistan who entered the country via the southern border earlier this year seeking asylum. The Uzbeks, according to a report from CNN, were assisted in their crossing by a human smuggler known to have ties to the ISIS terror group in the Middle East.

While federal authorities say that no specific plot has been associated with the recent arrivals, the episode was alarming enough to make it into an urgent classified intelligence briefing that circulated among top officials in the Biden administration earlier this month. The fear is that the porous border with Mexico could prove to be a soft spot that international terror networks might be willing to exploit.

Federal officials have yet to locate all the individuals who applied for asylum at the border and were released pending immigration hearings. They have, however, been assisted in their search by authorities in Turkey, who arrested the smuggler associated with the group at the behest of the United States.

“There was no indication — and remains no indication — that any of the individuals facilitated by this network have a connection to a foreign terrorist organization or are engaged in plotting a terrorist attack in the United States,” a spokesman for the National Security Council told CNN.

A frequent critic of the administration’s border policies, Congressman Darryl Issa, and other Republicans in Congress have warned in the past that the influx of asylum-seekers in recent years presents a national security threat to the country. After an Afghan national on a terror watchlist was apprehended crossing the border in Mr. Issa’s California district in May, the congressman promised to hold the administration accountable for any calamities that arise out of the crisis at the border.

“Biden’s open borders aren’t just a gateway to five million illegals, record human and child trafficking and the deadliest drug crisis in our history,” Mr. Issa said in a statement at the time. “Biden’s reckless policy is also an open invitation to even the most wanted terrorists in the world to come to America. They know they’ll never have to leave. The nation knows what’s going on and this president has only begun to be held accountable for what he has done.”