Weisselberg, the longtime chief financial officer of the Trump Organization, is reportedly receiving immunity to speak with federal prosecutors who are investigating Cohen's campaign finance violations.
On Tuesday, the president's longtime personal lawyer and "fixer" Michael Cohen pleaded guilty to eight violations of federal campaign-finance, bank and tax laws. David Pecker has been a close friend of Donald Trump for decades; his cooperation with federal prosecutors raises the prospect of new information about Trump's past behavior.
Separately, the Manhattan district attorney has launched a preliminary investigation into whether the Trump Organization falsified business records relating to payments made to Cohen, a source confirmed to CBS news.
Weisselberg, the 71-year-old Trump Organization CFO, is intimately familiar with Trump's business dealings, having overseen his corporate ledgers through his rise in the NY real estate world and his global dealings in the years before he launched his presidential bid.
Prosecutors also said someone believed to be Pecker, working with a company editor, alerted Cohen that adult film star Stormy Daniels, whose real name is Stephanie Clifford, meant to talk about her affair with Trump from 2006. He also denies having a sexual relationship with either of the women, former Playboy playmate Karen McDougal and and adult film star Stephanie Clifford, who is known as Stormy Daniels.
He was summoned to testify earlier this year in the investigation into Cohen, Donald Trump's longtime former lawyer, USA media report.
Cohen mentioned Weisselberg on a secret recording that Cohen made in September 2016 and which was aired on CNN last month.
Trump attacks on Mueller probe are becoming less effective, new poll suggests
Why does it matter that Trump lied to the American people and won't admit it? Underwood and Democratic Gov. Those are not the words of some two-bit hoodlum who feels the law closing in.
"Impeachment would not remedy Trump's unconstitutional presidency because it would leave in place his vice president, White House staff and Cabinet, as well as all the executive orders he issued and all the legislation he signed, and the official record of his presidency", Reich wrote.
On the tape, Mr. Cohen is heard saying: "I've spoken to Allen Weisselberg about how to set the whole thing up".
However, Cohen reportedly told lawmakers behind closed doors previous year that he didn't know of any foreknowledge by Trump of the meeting.
Giuliani has said the payments were personal matters not subject to campaign finance law.
Cohen failed to report more than $4 million in income, according to the criminal information filed against him, resulting in his avoidance of more than $1.4 million in taxes he would have owed the Internal Revenue Service.
People shop in the President Donald Trump campaign store in the lobby of Trump Tower in New York City, New York, U.S., August 24, 2018.
Manafort was the first person to be tried in the highly sensitive investigation of suspected collusion between the Trump team and Moscow during the 2016 election. Moscow has denied it meddled in the election.