In a Brooklyn courtroom on Monday afternoon, lawyers for journalists and others argued that documents related to a former business associate of Donald Trump should be unsealed, saying they could have new significance now that the real estate magnate has been elected president.

Judge Pamela Chen in the U.S. District Court for the Eastern District of New York listened to debate on the unsealing of documents related to Felix Sater's criminal past. The Russian-born American was for more than a decade an informant for federal prosecutors and the FBI, cooperating on organizations such as Al Qaeda, Russian organized crime and La Casa Nostra, to avoid prison for his part in a $40 million stock fraud scheme for which he was convicted in 1998.

Trump reportedly tapped Sater as a senior adviser for his real estate ventures in the 2000s, in 2003 announcing plans to build a hotel complex in Phoenix with Sater's Bayrock Group. Even after elements of his background were disclosed, resulting in his exit from Bayrock, Sater remained in Trump's orbit, according to The Washington Post, using the Trump Organization office space and business cards.

Trump has since attempted to distance himself from Sater, saying in sworn testimony in 2013 that he wouldn't recognize him if they were in the same room.

From 1998 until 2012, the entire record of Sater's prosecution in the Eastern District was kept under seal, including the docket itself. Even as parts of the record have come to light, and Sater himself has granted interviews to outlets like The Los Angeles Times and Narco News, many of his dealings remain under seal.

At Monday's hearing, the judge and lawyers were instructed to refer to him as "John Doe," even though all parties acknowledged his identity was widely known.

Lawyers representing the government and Mr. Sater argued that documents under seal, if made public, could pose a threat to his safety.

Richard Lerner, an attorney arguing for the unsealing, said that's not the case, pointing out that much of Sater's activities are already in the public domain and have been for quite some time. While exactly what Lerner did or told federal investigators is not known, "for First Amendment purposes, theoretical isn't enough," he said.

"We have managed to go two days totally open, [and] the world hasn't come to an end yet," said attorney Henry Kaufman, referring to a tweet from journalist David Cay Johnston on Friday announcing the hearing.

Kaufman, who specializes in First Amendment and media law, filed an amicus brief on behalf of investigative journalists and on Monday asked that at least the motions for unsealing documents on Sater be released. "I've been like a dog with a bone on this," he said.

John Langford, who is representing Forbes Media and investigative journalist Richard Behar, argued that unsealing the documents is a question of right of access and noted that Sater pleaded guilty to racketeering 19 years ago. "The genie can't be put back in the bottle" in information that's already in the public domain, he said.

This is not the first time the matter of unsealing records on Sater has made it to the courts -- similar efforts have been made in the past. But Trump's election has renewed interest in the matter, especially in light of a report from The New York Times that in January Sater met with Trump's personal attorney, Michael Cohen, and a Ukranian lawmaker in a New York hotel regarding a pro-Russian peace deal for Ukraine.

"The public needs to know the length of their relationship and the nature of the relationship and what kind of a person [Sater] is," Lerner said on Monday. As Newsweek notes, it is unclear what acts by Trump could be construed as criminal.

On Tuesday, a number of documents related to the case had been made available online.

- Correction: John Langford represents Forbes Media and Richard Behar, co-intervenors on the case. A previous version of this story said Langford represents Behar and misidentified him as a Forbes staffer, which he is not.