The investigation comes as administration officials have fielded complaints about how Kristi Noem’s top adviser, Corey Lewandowski, dealt with companies seeking federal contracts.
Airport security officials have been sharing passenger data with immigration agents, but the program received little attention until videos captured a woman and her daughter being detained at San Francisco’s airport.
The Transportation Security Administration began sharing passenger information with immigration officials a year ago, highlighting fliers who were on a list of people to be deported.