(CNN) At least two dozen people — from Mar-a-Lago resort staff to members Donald TrumpThe inner circle at the Florida estate — has been subpoenaed to testify before a federal grand jury investigating the former president’s handling of classified documents, multiple sources familiar with the investigation told CNN.
On Thursday, Trump’s communications aide, Marco Martin, who worked at the White House and later traveled with Trump to Florida, appeared before a grand jury in Washington, DC. One of Special Counsel Jack Smith’s senior attorneys was involved in the interview.
Martin, who is among a small group of former White House advisers who will remain on the job after Trump leaves office, declined to answer any questions when approached by a CNN reporter.
Smith has sought testimony from several people close to Trump — from his own lawyers representing him in the case to Mar-a-Lago grounds staff, housekeepers and restaurant servers, the sources said.
Employees are of interest to investigators because of what they have seen or heard in their daily duties around the estate, including seeing boxes or documents in Trump’s office suite or elsewhere.
“They’re casting a very wide net — anyone and anything could have been seen,” said a source familiar with the Justice Department’s efforts.
For example, federal investigators have already spoken to investigators with a Mar-a-Lago employee seen on security camera footage moving boxes from a storage room with Trump aide Walt Nauta.
According to sources and federal election records, many Mar-a-Lago employees are represented by consultants paid by Trump Organizations.
The Justice Department has been investigating the mishandling of national security records and potential sanctions for about a year. FBI agents recovered more than 100 classified documents during a search at Mar-a-Lago last summer. Since then, Trump’s legal team has turned over additional classified material.
The federal investigation previously brought up top Trump advisers such as former White House Vice President Dan Scavino and former Trump adviser and Pentagon official Kash Patel.
Meanwhile, Smith is pursuing Trump defense attorney Evan Corcoran. During his appearance before the grand jury, Corcoran declined to answer questions about conversations with Trump regarding classified documents, citing attorney-client privilege. Prosecutors are asking a judge to hold him accountable because the conversations could be part of the commission of a crime or fraud.
A ruling on Corcoran is expected early this week from DC District Court.