Material from a binder with highly classified information connected to the investigation into Russian efforts to meddle in the 2016 election disappeared in the final days of Donald J. Trump’s presidency, two people familiar with the matter said.

The disappearance of the material, known as the “Crossfire Hurricane” binder for the name given to the investigation by the F.B.I., vexed national security officials and set off concerns that sensitive information could be inappropriately shared, one of the people said.

The material’s disappearance was reported earlier Friday by CNN. The matter was so concerning to officials that the Senate Intelligence Committee was briefed about it last year, a U.S. official said.

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