The Department of Homeland Security accidentally informed the Cuban government that some migrants targeted for deportation had requested U.S. protection from officials in their native country.
Some Cuban migrants had expressed concern about persecution or torture by government officials if they returned to the island, the Los Angeles Times reported Tuesday.
Immigration and Customs Enforcement (ICE) officials responded by pausing their efforts to deport the Cubans in question and are considering releasing them from U.S. custody.
Federal regulation generally forbids the release of asylum seekers' personal information without sign-off by top Homeland Security officials.
"The words egregious and illegal don't go far enough," said Robyn Barnard, associate director of refugee advocacy at Human Rights First, the Times reported. "And this is not any foreign government, but a government we have irrefutable evidence routinely detains and tortures those they suspect of being in opposition to them."
Barnard added that the inadvertent disclosures created a "nightmare scenario" for the Cuban migrants.
ICE officials accidentally posted the names, birth dates, nationalities and detention locations of 6,252 immigrants who claimed to be fleeing torture and persecution to the DHS website, the Times reported.
The November disclosure triggered a massive effort by the agency to probe the causes of the error and reduce the risk of retaliation against immigrants whose information was exposed.
Earlier this month, a DHS official "unintentionally" indicated that some of the 103 Cubans who could have been placed on a deportation flight had been affected by the late November data dump, an ICE official told the Times.
Forty-six of the 103 Cubans that DHS discussed with the Cuban government were affected by the leak.
The Times said ICE officials were in the process of contacting the Cubans whose information was disclosed, as well as any attorneys they might have.
Reps. Norma Torres, D-Calif., and Nanette Diaz Barragán, D-Calif., were among lawmakers who sent a letter to ICE leadership concerning the leak.
"We believe that ICE's failure to comply with simple regulations to protect asylum seekers have potentially endangered the lives of these vulnerable individuals and their families and urge you to take immediate action to ensure the privacy of this and other sensitive information held by the agency," the letter stated.
"We are deeply troubled by this news because federal law mandates that the information of people seeking asylum is to be kept confidential. Several of us frequently receive visits from individuals risking life and livelihood to help their communities thrive in the face of repressive regimes.
"Some of these courageous individuals go on to seek asylum in the United States — and it is unacceptable to put their information into the hands of bad actors."