The Justice Department and the F.B.I. are investigating Cambridge Analytica, the now-defunct political data firm, and have sought to question former employees and banks that handled its business, according to an American official and other people familiar with the inquiry.
Prosecutors have questioned potential witnesses in recent weeks, telling them that there is an open investigation into Cambridge Analytica — which worked on President Trump’s election and other Republican campaigns in 2016 — and “associated U.S. persons.” But the prosecutors provided few other details, and the inquiry appears to be in its early stages, with investigators seeking an overview of the company and its business practices.
