Special counsel Robert Mueller's Russia investigation is now focusing on the financial ties President Donald Trump's associates might have to Moscow "as one of the most fertile avenues for moving their probe forward," CNN reported Thursday.
"This is like any investigation," one person briefed on the probe told the cable network. "You start at the core and then move to the periphery.
"You have to explore the finances," the person added. "Where this is going is no different from any investigation."
According to "sources" cited by CNN, the FBI is reviewing financial records related to the Trump Organization, as well as to the president, his associates, and his family members — including Donald Trump Jr.
In addition, investigators have "combed through the list of shell companies and buyers of Trump-branded real estate properties and scrutinized the roster of tenants at Trump Tower reaching back more than a half-dozen years," CNN reported.
"They've looked at the backgrounds of Russian business associates connected to Trump surrounding the 2013 Miss Universe pageant."
However, "CNN could not determine whether the review has included his tax returns."
The probe also has included Trump Jr.'s meeting in June 2016 with a Russian lawyer under the guise of receiving damaging information about Democrat Hillary Clinton.
Reuters and The Wall Street Journal reported Thursday that Mueller impaneled a grand jury in Washington in the Moscow probe and the jury had subpoenaed Trump Jr. on the Russia meeting.
President Trump has slammed the Moscow probe as a "witch hunt."
"President's outside counsel has not received any requests for documentation or information about this," Jay Sekulow, member of President Trump's outside counsel, told CNN.
"Any inquiry from the special counsel that goes beyond the mandate specified in the appointment we would object to."
Though the president has insisted his companies have "no involvement with Russia" and he has "no loans, no nothing" from the Kremlin, his lawyers have disclosed some exceptions, according to CNN.
These include the 2013 Miss Universe pageant in Moscow and the 2008 sale of a Florida mansion he owned to a Russian billionaire.
The deals earned President Trump more than $100 million, according to his lawyers.
In addition, Mueller's team is probing whether any financial rules were broken and whether any such business ties could put the president or his associates "in a compromising position," CNN reported.
"There's always been a concern about his exposure to blackmail in his financial dealings," the person briefed on the inquiry said.
However, some of those under scrutiny are accusing Mueller's team of a bait-and-switch approach — charging the investigation could eventually end up focusing on financial dealings versus solely on alleged ties to Russia.
"They launch an investigation into collusion in the election, then they go after people because of old business matters that have nothing to do with collusion," one person who has a client under investigation told CNN.