The longtime chief financial officer of Donald Trump's real estate company is under criminal investigation by the New York Attorney General, according to multiple reports.

This revelation comes as NY Attorney General Letitia James' office also confirmed that its investigation of the Trump Organization "is no longer purely civil in nature" and that two assistant attorneys general have apparently joined Manhattan District Attorney Cy Vance's criminal investigation into the company. The DA's investigation has been looking at whether the company shifted values of properties in order to get loans and tax breaks.

James' office informed the Trump Organization that it opened the criminal investigation into the taxes of Allen Weisselberg, who has been the company's chief financial officer for over 40 years, back in January, according to the NY Times.

CNN reports, "One theory prosecutors are exploring is whether there was a practice at the Trump Organization to dole out benefits to employees instead of salaried compensation to lower its payroll taxes, people familiar with the investigation said. Recently, prosecutors have started looking into rent payments on Weisselberg's Manhattan apartment, the people said." Weisselberg's attorneys declined to comment, according to CNN.

Last month, investigators from the Manhattan DA's office seized boxes of financial records from Weisselberg's former daughter-in-law, Jennifer Weisselberg. The Washington Post reported at the time, "The subpoena...ordered Jennifer Weisselberg to produce all of the records she possesses for her ex-husband’s bank accounts and credit cards plus his statements of net worth and tax filings. [Her ex-husband] Barry Weisselberg is a Trump Organization employee and manages an ice rink for the company in Manhattan’s Central Park. The subpoena asks specifically for records related to the Trump Organization and Wollman Rink."

“My knowledge of the documents and my voice connect the flow of money from various banks and from personal finances that bleed directly into the Trump Organization,” she told the Washington Post.

The Times also notes that Vance's team is also looking at "fringe benefits, subpoenaed records from [Allen] Weisselberg’s bank and the private school in Manhattan that his grandchildren have attended."

While Barry Weisselberg testified during divorce proceedings that his father paid for their children's private school tuition at Coumbia Preparatory (where Trump's youngest son, Barron, attended school before moving to the White House), Jennifer Weisselberg contended that "Donald wrote" at least some tuition "checks."

The former president released a defiant statement on Monday about news of the attorney general joining the Manhattan DA's investigation. "There is nothing more corrupt than an investigation that is in desperate search of a crime," he said. "But, make no mistake, that is exactly what is happening here."

Trump's former lawyer and fixer, Michael Cohen, spoke to MSNBC's Joy Reid and said he believes that Trump will "flip on all of them"—his employees and even his own children.