All attention was focused on Mar-a-Lago. Some of the action was in Bedminster.

Despite all the attention during the investigation into former President Donald J. Trump’s handling of classified documents about Mar-a-Lago, his private Florida club and residence, another property owned by Mr. Trump has played a crucial, albeit quieter, role in the business: his 520-acre golf club in Bedminster, NJ

Mar-a-Lago made headlines last August after federal agents descended on the compound and snatched away a trove of more than 100 classified documents, and photos of boxes of presidential documents piled there — including in a bathroom — helped explain why prosecutors chose to indict him this month.

But Bedminster, where Mr. Trump spends his summers, also appears to have been a focus of investigators, a focal point in the conflict between prosecutors and Mr. Trump’s lawyers, and the scene of a pivotal episode in Mr. Trump: A rally in which he was recorded showing off what he described as a “highly confidential” plan to attack Iran.

That audio recording, published Monday by The New York Times, was the latest piece of evidence that puts Bedminster on nearly equal footing with Mar-a-Lago as a key location in the case being prosecuted against Trump by Special Counsel Jack Smith. Previously unreported details of the investigation show prosecutors working for Mr Smith subpoenaed surveillance footage from Bedminster, just as they did from Mar-a-Lago, and fought a pitched battle with Mr Smith’s lawyers late last year. Trump on how best to search the New Jersey estate.

At one point in the early fall of last year, investigators even went so far as to discuss the execution of a search warrant in Bedminster, according to two people briefed on the matter. Investigators were concerned that more documents were stashed in the club and the only way to account for them was to search the premises. But one of the people said the Justice Department probably had no reason to get an order from a judge.

The discussions about the order took place around the time that Jay Bratt, the Justice Department’s top counterintelligence official, told Mr. Trump’s legal team that prosecutors believed Mr. Trump had further classified material in his possession.

Mr. Trump acquired Bedminster in 2002 and uses it as a seasonal getaway from both New York and South Florida. The property’s role as a summer residence figured in the suit filed by Mr Smith: Prosecutors said Mr Trump’s co-defendant in the case, Walt Nauta, loaded Mar-a-Lago boxes onto a plane “that flew Trump and his family up north for the summer” on the same day Mr. Bratt showed up in Florida to collect all the classified documents that were left there.

As for the recording of Mr Trump, it was taken in Bedminster in July 2021 at a meeting attended by two of his aides – identified by people in the know as Margo Martin and Liz Harrington, who have seen some of Mr Trump attended. Trump’s book interviews that summer — as well as by a publisher and writer working on a memoir for Mark Meadows, Mr. Trump’s last White House chief of staff.

On the recording, Mr. Trump can be heard rustling through the papers and describing to his guests a “secret” plan regarding Iran that he said was drawn up by General Mark A. Milley, the Chairman of the Joint Chiefs of Staff, and the Department of Defense. Mr. Trump described the document in an attempt to refute one bill that General Milley feared having to dissuade him from triggering a crisis with Iran in the period after Mr Trump lost his re-election bid at the end of 2020.

“This totally wins my case, you know,” Trump says, adding that the papers he apparently showed were “highly confidential” and “secret.”

One of the women heard speaking on the tape was Mrs. Harrington, three experts said. Ms. Harrington, one of the most aggressive defenders of Mr. Trump on Twitter, did not respond to questions about whether she is one of the voices talking on the recording as Mr. Trump appears to be showing a piece of paper.

Mrs. Harrington; Mrs. Martin, who worked for Mr. Trump in the White House; and the other participants in the meeting could be key witnesses if Mr. Trump’s case goes to trial, as they can describe firsthand what he showed when he discussed the Iran plan. A lawyer for Ms Martin declined to comment.

People close to Mr Trump have suggested that the recording does not specify whether Mr Trump actually showed anyone a confidential document – and he told Fox News’ Bret Baier last week that there was “no document”. Yet the indictment clearly states in its first few pages that he presented a document, a claim that appears to be supported by his own words, as recorded in the recording.

In an interview with Fox News on Tuesday, Trump did not repeat the claim that there was no document, but insisted he had done nothing wrong.

“I said it very clearly – I had a whole desk full of papers, mostly newspaper articles, copies of magazines, copies of different plans, copies of stories, dealing with a lot of subjects, and what was said was absolutely fine,” said Mr. Trump, when asked how he reconciled the recording with what he told Mr. Baier. “I’m not doing anything wrong. I do things right. I am a legitimate person.”

Steven Cheung, a spokesman for Mr Trump, said the full context of the recording showed the former president did “nothing wrong at all”.

Shortly after the Bedminster rally, people in Mr Trump’s orbit knew something unusual had happened, according to a person with knowledge of the events.

The indictment describes Mr Trump’s meeting with the people working on the book and members of his staff, “none of whom had security clearance”. It also says that Mr. Trump “showed and described a ‘plan of attack’.”

Mr. Meadows’ book contains a reference to a document that he claimed Mr. Trump said General Milley had typed himself.

“The president recalls a four-page report typed by Mark Milley himself,” Mr. Meadows’ book read. “It contained the general’s own plan to attack Iran, which would involve deploying massive numbers of troops, something he urged President Trump on more than one occasion during his presidency. President Trump rejected those requests every time.”

People close to General Milley have denied that he pushed to attack Iran.

Mr. Smith’s indictment suggests prosecutors obtained a large amount of Mar-a-Lago surveillance footage, some of which show Mr. Nauta, Mr. Trump’s co-defendant and personal assistant, moving boxes in and out of a storage unit . in the basement of the complex.

The move of those boxes — undertaken at the request of Mr Trump, prosecutors say — is at the heart of a conspiracy charge accusing Mr Trump and Mr Nauta of obstructing the administration’s efforts to recover all classified material. to demand that Mr. Trump take. him from the White House.

But prosecutors have also issued at least one subpoena for surveillance camera footage from Bedminster, according to two people familiar with the case. The subpoena for those images came some time after the government’s request for the Mar-a-Lago footage, the people said, though it remains unclear what the footage shows or exactly why prosecutors sought to obtain it.

One thing is certain, though: Even after the FBI searched Mar-a-Lago, Mr. Bratt and his team remained concerned that Mr. Trump was still holding classified documents in violation of a subpoena for them the administration had made. issued three months earlier. So in September — a month after the Mar-a-Lago search — prosecutors reached out to Trump representatives to give the former president another chance to return relevant material, according to sealed court documents described in The Times.

Initially, Mr. Trump’s lawyers refused to further search his property or provide an affidavit declaring that everything had been turned over, the court documents said, according to a person who was aware of its contents. Their refusal caused the lawyers to question the scope and validity of the initial subpoena and argue that Mr. Trump’s presidential office could incriminate itself if more classified documents were discovered and returned.

The government responded by filing a motion to enforce compliance with the original subpoena, and a hearing was scheduled for late October for Judge Beryl A. Howell, who was then the chief judge of the Federal District Court in Washington.

One of Mr Trump’s former lawyers, Timothy Parlatore, has since suggested that Boris Epshteyn, another lawyer close to Mr Trump, “tried to interfere” with searches ordered by Trump’s legal team around that time . Mr. Parlatore made the comments about Mr. Epshteyn in a CNN interview last month citing his differences with Mr. Epshteyn as a major reason he had resigned as Mr. Trump’s representative. (He later said Mr Epshteyn was not at fault and called it a disagreement.)

Minutes before the hearing before Judge Howell, Mr Parlatore warned her and the government that a team of professionals with military training had searched Bedminster for classified material only days earlier. They were accompanied by another of Mr. Trump’s lawyers at the time, James Trusty.

But the Justice Department was unimpressed, according to court documents. Prosecutors complained that the search was limited to certain areas of Bedminster and was not accompanied by an affidavit detailing which areas of the club had been investigated.

Ultimately, Judge Howell ruled in favor of the government and ordered Mr Trump’s lawyers to take an affidavit about which parts of Bedminster had been searched. She also told the lawyers to make available a “custodian of records” for Trump’s presidential office to testify about the search before a grand jury.

Ben Protess, William K. Rashbaum And Adam Goldman reporting contributed.