(Image Credit: Charles Dharapak/AP Photo)

After two weeks of denials, Immigration and Customs Enforcement (ICE) officials have finally publicly acknowledged the release of more than 2,000 undocumented immigrants for budgetary reasons.

On Thursday at a hearing of the House Homeland Security Subcommittee, ICE Director John Morton admitted 2,228 were released for "solely budgetary reasons."

Morton took full responsibility for the decision, saying it was an ICE decision, not a White House decision.

"And I take full responsibility for the agency, for the management of our beds," he said. "And, as I have said and the secretary has said, you know, I regret that there is a level of surprise and questions about what we did."

He testified that the decision was made to release detainees to allow the agency to " stay within its budget." The other choice, he said, was to cut domestic investigators - money that is used to go after drug traffickers, alien smugglers, child pornographers and money launderers.

Of those released, 70 percent had "no record at all," while 10 were classified as level1 offenders - which includes aggravated assault and financial crimes. Another 159 were level 2 offenders, which includes those picked up for theft, larceny and DUIs; and 460 were level 3 offenders, which are misdemeanors and single DUIs.

Morton noted that authorities re-caught four of the level 1 offenders after releasing them, citing a computer error for their initial release.

"In some of those cases there was a question as to whether the records were accurately entered into our system," Morton said. "And when I had all of them looked at, there were a couple where the computer record didn't accurately reflect."

During testimony, Morton said Texas had the most detainees released, although no level 1 releases.

The Associated Press originally reported exclusively two weeks ago:

"Homeland Security Department released more than 2,000 illegal immigrants facing deportation from immigration jails in recent weeks because of looming budget cuts. It also planned to release 3,000 more during March."

ICE challenged the AP reporting, saying only "several hundred" had been released for budgetary reasons, and the rest cited by the AP were part of normal "ebb and flow" of ICE detention centers.

Homeland Security Secretary Janet Napolitano told ABC News the next day that "detainee populations and how that is managed back and forth is really handled by career officials in the field."

She added that she wished the release "hadn't been done all of a sudden" so people weren't surprised by it.

Napolitano added at a Politico-sponsored event the following week that "several hundred are related to sequester, but it wasn't thousands."

The immigrants who were released still are under the supervision of ICE and are required to report to immigration hearings. The cost to keep a person in a detention center is $122 per person, per day - compared to $7 per day for alternative detention, which involves supervised release and which Morton said these detainees were released to.