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.
The investigation compounds the woes of a firm that has come under intense scrutiny from lawmakers and regulators in the United States and Britain Reported in March that it had harvested private data from more than 50 million Facebook profiles, and that it may have violated American election laws.
This month, Cambridge Analytica announced that it would shut down and declare bankruptcy, saying that negative press and cascading federal and state investigations had driven away customers and made it impossible for the firm to remain in business.
Cambridge Analytica, the Justice Department and the Federal Bureau of Investigation declined to comment.
The company, whose principal owner is the wealthy Republican donor Robert Mercer, offered tools that it claimed could identify the personalities of American voters and influence their behavior. Its so-called psychographic modeling techniques, which were built in part with the data harvested from Facebook, underpinned Cambridge’s work for the Trump campaign in 2016.
But the firm found itself at the center of a trans-Atlantic furor after the Times and Observer articles appeared. It was then dealt another blow when a British news channel broadcast undercover video in which Alexander Nix, the company’s suspended chief executive, suggested that the company had used seduction and bribery to entrap politicians and influence foreign elections.
The federal investigation in the United States appears to focus on the company’s financial dealings investigators have reached out to the company’s banks, for instance and how it acquired and used personal data pulled from Facebook and other sources, according to the American official, who was briefed on the inquiry, and other people familiar with it.
In addition, the investigators have contacted Facebook, said the official, who spoke on the condition of anonymity to discuss the investigation. The official would not provide any other details, and Facebook declined to comment.
In a sign of the inquiry’s scope, one of the prosecutors involved is the assistant chief of the Justice Department’s securities and financial fraud division, Brian Kidd. The effort is being assisted by at least one agent who investigates cybercrime for the F.B.I., those people said.
Mr. Kidd traveled to London this month with another Justice Department prosecutor and an F.B.I. agent to interview Christopher Wylie, a former Cambridge Analytica employee who has emerged as one of the firm’s fiercest critics.
“I can confirm that I’ve been contacted by the F.B.I. and the Department of Justice, and answered preliminary questions,” Mr. Wylie said in a brief interview. “We plan to meet again to provide substantive answers to the investigators.”
It was not clear whether the investigation is tied to the inquiry being led by Robert S. Mueller III, the special counsel, who is examining whether Mr. Trump or any of his associates aided Russia’s effort to interfere in the presidential election.
Prosecutors from Mr. Mueller’s team questioned at least two Cambridge executives last December in Washington, according to one company official.
The employee, who asked to remain anonymous to describe confidential internal matters, added that the inquiry appeared to be perfunctory. There have been no other concrete signs from Mr. Mueller’s team that Cambridge is a focus of their efforts.
The Justice Department’s investigation is running parallel to a separate investigation by the National Crime Agency of Britain. There, investigators are examining a range of allegations, including whether Cambridge Analytica employees sought to bribe foreign officials, destroyed evidence, hacked computers and violated Britain’s Data Protection Act.
Mr. Wylie said he had been cooperating with the National Crime Agency. He has also provided testimony and internal Cambridge Analytica documents to Parliament.
“There is an international investigation being coordinated by the National Crime Agency in Britain, and I intend to be as helpful and cooperative as I can,” he said.
Cambridge Analytica has denied using Facebook data on the 2016 campaign. An internal audit commissioned by Cambridge described Mr. Nix’s statements in the video as an exaggeration.
Cambridge Analytica grew out of the SCL Group, a well-established British company that specialized in psychological research for defense and intelligence agencies but also worked on election campaigns, chiefly in developing countries.
In 2014, SCL executives persuaded Mr. Mercer to bankroll a new United States-based firm, Cambridge Analytica, that would break into the growing political data market with a promising new product: psychological profiles of millions of American voters.
The new company was overseen by Mr. Mercer’s daughter, Rebekah, and then adviser, Stephen K. Bannon, both of whom went on to enjoy influential positions in Mr. Trump’s circle before the president’s break with Mr. Bannon this year.
Also in 2014, a contractor for the new firm used quiz apps and other programs to gather private profile information from as many as 87 million Facebook users, data former Cambridge employees said provided the critical basis for the new company’s voter profiles.
It was reported in March that the company had sent personnel from Canada and Europe to work on various campaigns in the 2014 midterm elections and in 2016 campaigns, raising questions about Cambridge’s compliance with federal election law, which limits the involvement of noncitizens in election campaigns.
Over the past year, Cambridge’s efforts to break into commercial data and marketing work had suffered from the company’s association with Mr. Trump, according to former employees. And in the months before shutting down, Mr. Nix, the Mercer family and SCL’s owners had considered new ventures together.
One new firm, a British holding company called Emerdata, was formed in part to bring in new investors, according to a former employee. Emerdata’s directors, according to public records, came to include Johnson Ko Chun Shun, a Hong Kong financier and business partner of Erik Prince, founder of the private security firm formerly known as Blackwater.
Mr. Ko and Mr. Prince have links to the Chinese government: Citic, a state-owned Chinese financial conglomerate that for decades has employed the sons and daughters of the Communist Party’s elite families, is a major investor in Frontier Services Group, Mr. Ko and Mr. Prince’s Africa-focused logistics company.>