M. Evan Corcoran is pictured at the Brooklyn Federal Courthouse on September 20, 2022, in New York City.
CNN  — 

Donald Trump attorney Evan Corcoran appeared last month to testify before a federal grand jury in Washington, DC, that’s looking at the former president’s handling of national security records at his Mar-a-Lago residence, a source confirmed to CNN.

He was there for roughly four hours.

Bloomberg first reported that he had appeared.

Prosecutors asked Corcoran about what had occurred up until the August 8, 2022, search of Mar-a-Lago, which came after investigators found evidence that made them believe classified records kept at the Florida resort were moved and concealed – including questions about his interactions with Trump, another person familiar with the situation said.

The disclosure of Corcoran’s testimony comes amid a steady drip of recent moves by special counsel Jack Smith to obtain grand jury testimony from very close contacts of Trump, in many cases about what Trump was told and what he said at the end of his presidency and afterward.

It also comes amid an escalation of activity in Smith’s other Trump probe, looking into January 6, 2021, and efforts to impede the transfer of power following the 2020 election. Smith issued a subpoena in that investigation to former Vice President Mike Pence in recent days, seeking documents and testimony. Trump’s former national security adviser Robert O’Brien also received a subpoena, as CNN first reported.

Corcoran declined to answer some questions in the grand jury that would have divulged his advice to Trump and their conversations, citing attorney-client privilege, the person familiar added. The Justice Department has repeatedly tried in the investigation to force witnesses to answer questions they declined to respond to in the grand jury, but the courts will ultimately have to decide if Corcoran must say more.

As one of Trump’s primary criminal defense lawyers since he left the presidency, Corcoran has been in touch with federal investigators and the National Archives for much of the course of the Mar-a-Lago documents investigation.

He had drafted a letter signed by another attorney last June that said Trump’s team had done a diligent search and turned over classified records in their possession. Even still, the DOJ believed its investigation was being obstructed, prompting investigators to obtain a search warrant from a court in August.

Hundreds more records with classified markings were found, with additional being turned over by Trump’s lawyers to the DOJ in the past few months.

This story has been updated with additional details.

CNN’s Evan Perez and Zachary Cohen contributed to this report.