Hundreds of illegal immigrants from terror hotspots are using what critics describe as loopholes in U.S. immigration policy to try to remain in the country indefinitely, according to data obtained by Congress.

Taking a page from the playbook used by Central American women and children to gain U.S. entry, hundreds of immigrants from Egypt, Somalia, Pakistan, Iran and Syria caught entering the U.S. last year made asylum claims to avoid deportation – and, in doing so, asserted they had a “credible fear of persecution.”

This phrase is important because it allows them to be released and work in the U.S. Prior to 2009, the U.S. held in custody many asylum seekers entering the U.S. illegally until their cases were resolved in court -- but an Obama administration policy change allowed those fearing persecution to be released.

The finding that asylum seekers from turbulent Middle Eastern and African countries are now using this phrase to gain entry and remain on U.S. soil has raised security concerns on Capitol Hill.

"These numbers illustrate vulnerabilities throughout our immigration system," Rep. Ron DeSantis, R-Fla., said Tuesday. "Dangerous criminals and potential terrorists are gaming the system without consequence. The Obama administration is compromising our national security and safety for its political agenda."

DeSantis, chairman of the House Subcommittee on National Security, is set to hold a hearing Wednesday on the potential threat posed by these individuals in light of the Paris and Brussels attacks. His subcommittee obtained the findings on the methods being using to remain in the U.S. Witnesses set to appear at the hearing Wednesday are Ronald Vitiello, acting chief of the U.S. Border Patrol; and Brandon Judd, president of the National Border Patrol Council.

Stats obtained by the subcommittee from October 2014 to September 2015 show that the bulk of the “credible fear” claims still are coming from Central American and Mexican immigrants. But 80 were from Syrian nationals, 191 were from Pakistani nationals, and 776 were from Somalian nationals.

"They are coming through the backdoor," Judd said. "Do I believe they have a credible fear? In a small percentage, maybe. But the vast majority we arrest are telling our agents that they are coming because they know they will be released. That's why they are coming."

Judd said illegal immigrants have found a second loophole as well. By claiming they arrived in the U.S. before 2014, immigrants are able to avoid detention and deportation.

Here's why:

In January 2014, President Obama announced his “priorities” program, which ordered agents to worry chiefly about criminals, national security risks and illegal immigrants who came into the U.S. after that date. Judd claims supervisors at the Mexican and Canadian borders have told agents not to bother turning other immigrants over to Immigration and Customs Enforcement since "they won't be deported anyway."

"President Obama said we need to take these people out of the shadows. The fact is we took them out, and now we are releasing them right back into the shadows. What was the point?” he said. “The court system is so backlogged, we're told they are never going to see a judge anyway. So just let them go."

In the past, illegal immigrants from outside Mexico were subject to expedited removal. The process allowed agents to deport non-citizens without going through a formal and lengthy removal proceeding before an immigration judge.

Now, however, Judd said anyone who claims they've been living in the U.S. continuously from prior to 2014 is not even being turned over to ICE and given a “Notice to Appear” in court. Fox News confirmed the practice with sources in two border sectors.

"At least a NTA required them to show up in court. What we have now is amnesty through policy," Judd said. "We are flat-out letting them go."

Requests for comment from the Department of Homeland Security were not returned. 

William La Jeunesse joined FOX News Channel (FNC) in March 1998 and currently serves as a Los Angeles-based correspondent.