The White House said Wednesday that it didn't know that immigration officials were going to release hundreds of illegal immigrants to save money even as Republicans step up calls for more details of the release plan.

Rep. Michael McCaul, R-Texas, is demanding that the Department of Homeland Security explain why it is releasing the illegal immigrants now in police custody.

McCaul, chair of the House Homeland Security Committee, wrote to John Morton, director of Immigration and Customs Enforcement (which falls under DHS), asking him to provide the details of the release. ICE claims the prison release will be supervised and is necessary because of a 5 percent budget cut coming under Friday's sequester.

McCaul wants to know how many detainees are being released and why they were arrested in the first place.

McCaul is also demanding "the specific monitoring and tracking actions" ICE will use to keep track of those they have set free.

Republicans reacted angrily Tuesday when they learned of the plan by ICE to release "hundreds" of inmates.

"This decision reflects the lack of resource prioritization within the Department of Homeland Security and Immigration and Customs Enforcement and is indicative of the department's weak stance on national security," McCaul wrote.

On Wednesday, White House spokesman Jay Carney said ICE never told Obama or Homeland Secretary Janet Napolitano about the plan and that neither the president nor Napolitano played a role in developing it.

"The agency released these low-risk, non-criminal detainees under a less-expensive form of monitoring to ensure detention levels stayed within ICE's overall budget," Carney said.