The former White House chief of staff Mark Meadows told investigators he had no knowledge of Donald Trump either talking about or declassifying confidential information, it was reported on Sunday, potentially skewering the ex-president’s defense in his classified documents case. Meadows’ alleged admission to the special counsel Jack Smith, reported by ABC News, suggests Trump made no blanket declassification of secret papers later seized from his Mar-a-Lago resort by FBI agents, leading to 40 criminal counts against him. Trump, who pleaded not guilty to all charges, has insisted without proof he gave automatic clearance to every government document he took to Florida at the conclusion of his administration in January 2021. But his lawyers have not yet presented the defense in court and doing so could open the possibility of Meadows being called as a witness to contradict it, ABC said. According to ABC, Meadows also told Smith he was not involved in packing the boxes, did not witness Trump or anybody else doing so, and claimed he was unaware the former president was taking anything with him. If true, it would be extraordinary that one of Trump’s closest aides had absolutely no knowledge of anything to do with the retention of the documents. It might also suggest Trump knew what he was taking and planned and executed the operation himself. Trump’s former vice-president, Mike Pence, also said he was unaware of any standing order for declassifying documents. Asked about the report, he told ABC’s This Week: “There is a process that the White House goes through to declassify materials. I’m aware of that occurring on several occasions over the course of our four years but I don’t have any knowledge of any broad-based directive from the president.” Pence, now challenging his former boss for the Republican presidential nomination, added: “That doesn’t mean it didn’t occur. It’s just not something that I ever heard about.” Asked if Meadows, as Trump’s chief of staff, should have been aware of any such broad declassification order, Pence said: “I would expect so.” Meadows, who has remained publicly silent about the documents case, was indicted alongside Trump and 17 others last week by Fani Willis, the district attorney for Fulton county in Georgia who is investigating efforts to reverse Joe Biden’s win there in 2020. On Saturday, attorneys for Meadows asked a federal court to dismiss the state charges against him. Meadows claims his alleged actions, including participating with Trump in a phone call to the Georgia secretary of state, Brad Raffensperger, should be immune from state prosecution because they were performed in his capacity as a federal official. A 37-page document filed on Saturday with a US district court in Georgia asserted that Meadows’ actions were protected by the supremacy clause of the US constitution, under which federal officials are immune from state prosecution for acts committed within the reasonable scope of their duties. “The conduct charged here falls squarely within the scope of Mr Meadows’s duties as chief of staff and the federal policy underlying that role,” attorneys said in the filing. The document also claimed protection under the first and 14th amendments to the constitution. The filing came days after Meadows, a former North Carolina congressman, sought to have the case moved from Georgia’s Fulton County to federal court. In the investigation over the classified documents, ABC said, Meadows appeared before a federal grand jury investigating the classified documents in April. According to ABC’s sources, Meadows told the special counsel he made an offer to Trump to go through the boxes and retrieve classified documents after the National Archives first requested their return in 2021, but was turned down. ABC also claimed to have reviewed a draft copy of Meadows’ 2021 memoir, The Chief’s Chief, which Meadows allegedly asked to be rewritten to change a description of Trump’s discussion of a classified Iran war plan in front of unauthorized persons at his golf club in Bedminster, New Jersey. A reference to Trump’s handling of the document was removed from the final draft, ABC said, because it could be “problematic”. Audio of the meeting, heard by the Guardian, features Trump boasting about having a document on Iran from the “defense department”. Trump later claimed there was no document, and he was referring to news clippings. In a statement to ABC News, the Trump campaign accused the justice department of “selectively leaking incomplete information that lacks proper context”. Echoing language Trump has used in response to all his indictments, the statement said: “This witch hunt is nothing more than a desperate attempt to interfere in the 2024 election as President Trump dominates the polls and is the only person who will take back the White House.” Reuters contributed to this report