WASHINGTON — The F.B.I. and the special counsel’s office investigated whether a former Trump campaign adviser secretly worked for the Egyptian government to influence the incoming administration in the months before President Trump took office, according to several people familiar with the inquiry.
The former adviser, Walid Phares, was one of five Trump campaign aides investigated over their ties to foreign countries. Robert S. Mueller III took over the investigations after he was appointed special counsel in May 2017.
The decision to investigate Mr. Phares was based on highly classified information, the people said. Investigators examined the matter for months but ultimately brought no charges.
Though Mr. Mueller’s primary mandate was to examine Russia’s covert operation to sabotage the election and whether any Trump associates conspired, several Trump campaign advisers and transition team members elicited concerns at the F.B.I. because of their overseas contacts and the possibility that a variety of foreign governments might have been trying to secretly use the advisers to advance their agendas.
Mr. Phares declined to comment, as did a Justice Department spokeswoman.
The C.IA. director at the time, Mike Pompeo, was briefed on the investigation, suggesting that the agency might have obtained a tip from an Egyptian source that prompted the F.B.I. inquiry, people familiar with it said.
Mr. Phares joined the foreign policy team that Mr. Trump assembled in the spring of 2016 as his surprise ascendance to the Republican nomination for president prompted the party establishment to openly question his lack of foreign policy experience. But the team was almost immediately derided as a collection of fringe thinkers and unknowns.
The F.B.I. investigated four other Trump campaign advisers over their ties to Russia as part of the bureau’s original inquiry into Moscow’s election interference and later began examining Mr. Phares’s ties to Egypt as part of that investigation.
Two others in the foreign policy group, Carter Page and George Papadopoulos, drew F.B.I. scrutiny over their Russia connections, as did Michael T. Flynn, a retired three-star Army lieutenant general who advised the campaign and served as Mr. Trump’s first national security adviser, and the onetime campaign chairman Paul Manafort.
Mr. Flynn and Mr. Papadopoulos eventually pleaded guilty to lying to investigators, and Mr. Papadopoulos served a brief prison sentence. Mr. Flynn has done an about-face, and the Justice Department has sought to withdraw the charge against him in a move that former law enforcement officials have said further politicized the department. The case is playing out in court.
Mr. Manafort and another Trump associate, the president’s longtime friend Roger J. Stone Jr., were convicted of multiple felonies and given yearslong prison sentences.
Mr. Page was never charged with a crime, and the investigation into him became the focus of intense scrutiny after investigators botched applications for court permission to secretly wiretap him.
Perhaps the most prominent of the early Trump foreign advisers, Mr. Phares frequently appeared on Fox News to discuss the dangers of Islamic terrorism and Shariah law. A Lebanese-born Maronite Christian, he previously served as an adviser to Senator Mitt Romney, Republican of Utah, when he ran for president in 2012.
J.D. Gordon, a former Pentagon official who worked for the Trump campaign as a national security adviser, told investigators that he hired Mr. Phares for the foreign policy team. He said that Mr. Phares quit the campaign in May and then went to work as a Trump surrogate, adding that Jared Kushner, the president’s son-in-law and senior adviser, would not let Mr. Phares have a job in the administration. It was not clear why.
The Obama administration had been critical of the Egyptian government, accusing President Abdel Fattah el-Sisi’s administration of arbitrary killings and politically motivated arrests in a crackdown on freedom of expression after he seized power in a military takeover.
Forging new ties with Mr. Trump, who seemed less concerned with the country’s human right’s record, would have benefited Mr. el-Sisi both politically and militarily.
Hints of the investigation into Mr. Phares have emerged in redacted special counsel documents and in F.B.I. interview notes obtained by BuzzFeed News in an open records lawsuit. CNN also sued for the records.
Mr. Phares had high-level contacts in the Egyptian government and connections to a deputy minister for education, another Trump campaign official, Sam Clovis, told Mr. Mueller’s investigators. Mr. Phares told Mr. Clovis that he had friends who could broker meetings between the campaign and the Egyptian government, but Mr. Clovis rejected that idea, he said.
Mr. Clovis and Mr. Phares had met with an Egyptian official at a hotel in Georgetown, according to Mr. Clovis, who could not recall the man’s name for investigators. Mr. Phares tried to set up another meeting with the official, but Mr. Clovis demurred.
Another campaign official, Rick Dearborn, told investigators that Mr. Phares was involved in reaching out to Egypt on behalf of the campaign and had an “existing relationship” with the Egyptians.
Then the Republican nominee for president, Mr. Trump met in September 2016 with Mr. el-Sisi. Mr. Phares took credit for that meeting, telling Mr. Trump’s daughter Ivanka in an email shortly beforehand that he had traveled to “Egypt last week, worked with them on the meeting between President Sisi and your father.”
“Great that the meeting will take place tomorrow,” Mr. Phares added in the email, according to congressional investigators. “This is a major victory in foreign policy. It will generate more votes.”
Mr. el-Sisi visited the White House a few months after Mr. Trump was elected, the first visit by an Egyptian president to Washington since 2009. The president has embraced Mr. el-Sisi, bestowing validation on a strongman who took power in a military coup and has cracked down on dissent as he consolidates power.
The special counsel’s report mentioned Mr. Phares by name more than a dozen times. At least one blacked-out portion of the report also makes reference to Mr. Phares, according to people familiar with the redacted text. In March 2017, Senator Richard M. Burr, Republican of North Carolina and the chairman at the time of the powerful Senate Intelligence Committee, disclosed to the White House Counsel’s Office that Mr. Phares was being investigated, according to notes taken by an official at the time.
And this month, the Justice Department released a copy of the memo signed by the former deputy attorney general Rod J. Rosenstein that laid out the scope of Mr. Mueller’s authorities. The memo cited investigations into Mr. Flynn, Mr. Page, Mr. Manafort and Mr. Papadopoulos. A fifth section was redacted.
Mr. Rosenstein was set to testify before Congress next week about the Russia investigation.
Katie Benner contributed reporting.