After tens of thousands of immigrants crossed the border into the U.S. this past summer, they faced immediate deportation, but many have failed to report to authorities within the required 15 day period, the Associated Press reported.

Questions about what would happen to them were avoided initially and Homeland Security Secretary Jeh Johnson and others said they faced deportation, but at least 70 percent of those immigrants have simply disappeared into the U.S.

This information came from a private meeting of the Homeland Security Department in Washington Wednesday, a recording of which was obtained by the Associated Press, who found out that, though the specific number was not mentioned in the recording, about 41,000 undocumented immigrants failed to appear at federal immigration offices.

A number of families. came into the U.S. since last October, and of those a few hundred families have already been deported.

U.S. detention centers can only hold about 1,200 immigrants.

At least 860 people were caught at the border since May but only 14 had reported to immigration offices, the AP reported.

The newest numbers found out through this recording are significantly higher than the about 25 percent who typically don't show up for court hearings.

The practice of releasing undocumented immigrants and expecting them to report back to federal offices in 15 days is criticized by Republican lawmakers, since it is easy to disappear in that time.

But the President's administration faced a dilemma since, of the 66,000 immigrants who have come into the U.S. since October, at least 60,000 are from the Central American countries of El Salvador, Guatemala and Honduras, so they could not be immediately returned.

This has been the reason for an increase in the number of detention facilities recently, to prevent the immigrants from being released. But even that has been criticized by advocates who say that many of those kept in detention will eventually win lawful asylum in the country.