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WASHINGTON — The Department of Homeland Security and the House Homeland Security Committee are investigating whether U.S. border agents have been targeting journalists for questioning, according to a statement from Customs and Border Protection and a letter to CBP from the chair of the committee.

The statement and letter were in response to an exclusive story from NBC News and San Diego's KNSD-TV story that revealed CBP officials in the San Diego sector had compiled a list of 59 reporters, lawyers and activists to be pulled aside for further screening when crossing the U.S.-Mexico border.

The list includes 10 journalists, seven of them U.S. citizens, a U.S.-based attorney and others labeled as organizers and "instigators," 31 of whom are American.

Click here to read the original NBC News story

The Homeland Security Committee, led by Rep. Bennie Thompson, D.-Miss., asked CBP Commissioner Kevin McAleenan to provide a copy of the list with the 59 names, a copy of any dossiers on the individuals, an explanation of why each person was included on the list, an account of who had been stopped for screening and an account of any cell phone seizures.

A sample of names and photos from the list. KNSD blurred the names and photos of individuals who haven't given permission to publish their information. Obtained by KNSD

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“The appearance that CBP is targeting journalists, lawyers, and advocates, and particularly those who work on immigration matters or report on border and immigration issues, raises questions about possible misuse of CBP's border search authority and requires oversight to ensure the protection of Americans' legal and constitutional rights,” the letter said.

CBP said Thursday the DHS Inspector General is investigating the list. CBP is part of DHS.

The investigation began in February and is ongoing, according to CBP spokesman Andrew Meehan.

"CBP does not target journalists for inspection based on their occupation or their reporting. CBP has policies in place that prohibit discrimination against arriving travelers and has specific provisions regarding encounters with journalists," Meehan said in the statement.

Click here to read the letter from Congress

The investigation in being conducted "to ensure that all appropriate policies and practices were followed," the statement said. The names had been collected, Meehan said, to identify "individuals who may have information relating to the instigators and/or organizers" of attacks on Border Patrol agents that occurred during incidents at the border in November 2018 and January 2019.

Click here to read KNSD's story about the list

Meehan's statement did not say whether the Inspector General was also investigating whether CBP had a policy of stopping other professions, such as attorneys, at the border.

Those who had been stopped by CBP for additional screening described being asked for personal details, having to hand over their cell phones and being told they were being held as part of a “national security” investigation.

Meehan said it is standard practice to interview people who had been witnesses to an event under investigation, such as the unrest that occurred at the border between Tijuana, Mexico and San Ysidro, California in November 2018.

But many of those interviewed told NBC News they were not asked about that event, but instead about their work with asylum seekers.