The Department of Justice has issued a flurry of over 30 subpoenas to aides of former President Donald Trump, a source familiar with the federal investigation confirmed to Fox News. 

The Justice Department also seized phones from two top Trump advisers in the investigation, which aims to probe Trump's unsubstantiated claims of a rigged 2020 presidential election.

The dozens of new subpoenas mark a rapid escalation in pressure applied to the Trump camp by the DOJ.

Donald Trump's Mar-a-Lago

Former President Donald Trump's Mar-a-Lago resort in Palm Beach, Florida. (Charles Trainor Jr./Miami Herald/Tribune News Service via Getty Images)

TRUMP LAWYERS OPPOSE DOJ REQUEST TO CONTINUE TO USE CLASSIFIED DOCS SEIZED BY FBI DURING INVESTIGATION

The Justice Department is investigating allegations of phony Electoral College certifications from 2020 that declared Republicans were the electors voting for Trump and Mike Pence when in fact Democrats had won and voted for President Biden and Vice President Kamala Harris.

Timothy Parlatore, an attorney for Trump confidant and former New York Police Commissioner Bernard Kerik, confirmed that Kerik received a subpoena last Tuesday to appear before a federal grand jury in Washington, D.C., on Friday, Sept. 23.

The Department of Justice declined to comment.

Former President Donald Trump clapping

Former President Donald Trump speaks to supporters at a rally, Sept. 3, 2022, in Wilkes-Barre, Pennsylvania. (Spencer Platt/Getty Images)

SUPREME COURT DENIES TRUMP REQUEST TO BLOCK JAN. 6 COMMITTEE SUBPOENAS

Multiple reports have pointed to allegedly fake documents obtained by watchdog group American Oversight, which included paperwork from slates of Republican would-be electors in Michigan, Pennsylvania, Wisconsin, Nevada, Georgia, New Mexico and Arizona.

DOJ officials are waging a two-front war with ongoing investigations into both Trump's claims of a rigged election and the recent raid on Mar-a-lago that discovered a wealth of classified documents retained in his possession after leaving office.

Documents seized by FBI at Ma-a-Lago

This image contained in a court filing by the Department of Justice on Aug. 30, 2022, and redacted in part by the FBI, shows a photo of documents seized during the Aug. 8 search by the FBI of former President Donald Trump's Mar-a-Lago estate in Florida. (Department of Justice via AP)

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Trump’s legal team opposed the Justice Department’s motion to continue its review of classified documents seized by the FBI during its raid of Mar-a-Lago last month, slamming the entire investigation as "unprecedented and misguided," and one that has "spiraled out of control," while stressing that the government has not yet proven that the records "remain classified."

In a filing Monday morning, Trump’s legal team said the Justice Department is seeking to "limit the scope of any review of its investigative conduct and presuppose the outcome, at least in regard to what it deems are ‘classified records.’"