Trump attorney Evan Corcoran, following judge's ruling, appears before grand jury in documents probe

Trump attorney Evan Corcoran, following a judge's ruling piercing attorney-client privilege, appeared Friday before a grand jury probing President Donald Trump's handling of classified documents after leaving the White House and his possible obstruction of the government's efforts to retrieve them, sources familiar with the matter told ABC News.

An appeals court ruled Wednesday that Corcoran must testify in probe being conducted by special counsel Jack Smith.

The three-judge panel on the D.C. Circuit Court of Appeals rejected an effort by Trump's attorneys to block Corcoran from having to testify and hand over records to Smith's team, according to court records.

The appeals court ruling came five days after D.C. district judge Beryl Howell ordered that Corcoran should comply with a grand jury subpoena for testimony on six separate lines of inquiry over which Corcoran had previously asserted attorney-client privilege, sources familiar with the filing told ABC News.

According to sources familiar with the filing, Smith was seeking information from Corcoran on whether Trump or anyone else in his employ was aware of the signed certification that was drafted by Corcoran and signed by Trump attorney Christina Bobb, which was submitted in response to a May 11 subpoena from the DOJ seeking all remaining documents with classified markings in Trump's possession.

That certification was later discovered to be false, prompting the eventual court-authorized search of Trump's Mar-a-Lago estate in which FBI investigators recovered more than 100 classified documents -- including some located in Trump's personal office, according to previously released court documents.

Smith's investigators specifically wanted to ask Corcoran whether Trump was aware of the statements in the certification, which claimed a "diligent search" of Mar-a-Lago had been conducted, and if Trump approved of it being provided to the government, sources familiar with the filing said.

Trump has repeatedly denied any wrongdoing in his handling of classified documents.

"There is no factual or legal basis or substance to any case against President Trump," a Trump spokesperson told ABC News Wednesday. "The deranged Democrats and their comrades in the mainstream media are corrupting the legal process and weaponizing the justice system in order to manipulate public opinion, because they are clearly losing the political battle. The real story here is that prosecutors only attack lawyers when they have no case whatsoever."

Smith was appointed by Attorney General Merrick Garland in November to oversee the investigation into Trump's handling of classified documents as well as efforts by Trump and his allies to overturn the results of the 2020 election.

A spokesperson for the special counsel's office declined to comment.