Boris Epshteyn, a top adviser to former President Donald J. Trump, is scheduled to be interviewed on Thursday by prosecutors in the office of the special counsel Jack Smith, according to people familiar with the matter, the latest example of the Justice Department’s efforts to secure testimony and evidence from current and former close aides to Mr. Trump.
It remained unclear what subjects the prosecutors wanted to discuss with Mr. Epshteyn. But given his expansive ties to Mr. Trump, Mr. Epshteyn is in a position to provide information in both of the investigations that Mr. Smith is overseeing: one focused on Mr. Trump’s efforts to retain power after losing the 2020 election and the other centered on his handling of classified documents after he left White House.
Until recently, Mr. Epshteyn played a critical role coordinating Mr. Trump’s legal efforts in both inquiries. Serving as something like an in-house counsel, he has also worked with lawyers defending Mr. Trump in separate investigations by the district attorney in Fulton County, Ga., who is examining Mr. Trump’s potential interference in that state’s elections, and in Manhattan, where Mr. Trump was indicted last month in connection with a hush-money payment made to a porn star before the 2016 election.
The special counsel’s inquiries have focused in an unusually intense manner on the behavior of Mr. Trump’s lawyers, who have themselves faced an onslaught of criminal and civil exposure.
One lawyer, M. Evan Corcoran, had his attorney-client privilege with Mr. Trump brushed aside last month by a federal judge who compelled him to provide grand jury testimony in the documents inquiry after finding that his legal advice to the former president may have been used to further the commission of a crime.
Several of the lawyers — including Rudolph W. Giuliani — have received grand jury subpoenas as part of the investigations.
Mr. Epshteyn has also found himself entangled in multiple Trump investigations as a witness. In September, federal investigators seized his cellphone as part of the Justice Department’s inquiry into Mr. Trump’s attempts to stay in power and the attack on the Capitol on Jan. 6, 2021.
That same month, Mr. Epshteyn appeared before a special grand jury in Atlanta that was convened as part of the district attorney’s inquiry into possible election interference by Mr. Trump and his allies.
While it is not clear whether Mr. Epshteyn faces personal legal jeopardy in any of these cases, he has been linked to a critical element of Mr. Trump’s bid to hold onto power: the effort to name slates of electors pledged to Mr. Trump from swing states that were actually won by Joseph R. Biden Jr. Those false pro-Trump electors were ultimately put to use as part of a broader plan to block or delay congressional certification of Mr. Biden’s Electoral College victory during a joint session of Congress on Jan. 6.
In its final report issued last year, the House select committee investigating Jan. 6 noted that Mr. Epshteyn joined Mr. Trump’s legal team shortly after the election and was part of a group of lawyers given the task of investigating claims of voting fraud.
The panel also said Mr. Epshteyn was in contact with John Eastman and Kenneth Chesebro, two lawyers who were instrumental in devising and promoting the fake-elector scheme and a subsequent pressure campaign mounted against former Vice President Mike Pence to use the false slates to derail the election.
Mr. Epshteyn is also said to have played a role in connecting two lawyers who helped draft a sworn statement last June that a “diligent search” had been conducted at Mar-a-Lago, Mr. Trump’s private club and residence in Florida, and that no classified materials remained there.
That sworn statement is central to the documents inquiry because investigators ultimately found that it was untrustworthy and within two months executed a search warrant at Mar-a-Lago, hauling away about 100 additional classified documents.
In recent months, Mr. Epshteyn has frequently been at odds with other lawyers working with Mr. Trump, some of whom have complained about him to the former president. That led to an attempted intervention by some of the lawyers working with Mr. Trump, a number of whom have told colleagues they will not speak with him or share work information with him. Those lawyers were seeking to be able to speak to Mr. Trump directly about cases but felt hampered by Mr. Epshteyn.
But whether there will actually be a change in the legal team remains to be seen.
“Mr. Epshteyn continues to assist the president in coordinating the legal efforts, including battling against the witch hunts by the deranged, radical Jack Smith and the weaponized, woke Department of Justice,” said Steven Cheung, a spokesman for Mr. Trump.
