(CNN) Tax records that former President Donald Trump tried to keep secret for years are now in the hands of the New York district attorney.
Prosecutors obtained the records on Monday, just hours after the US Supreme Court denied Trump's last-ditch effort to keep the records private, a spokesperson for the district attorney said.
The millions of pages of documents, sources say, contain Trump's tax returns spanning from January 2011 to August 2019, as well as financial statements, engagement agreements, documents relating to the preparation and review of tax returns, and work papers and communications related to the tax returns.
Though the documents handed off from Trump's long-time accounting firm Mazars won't be released to the public because they're subject to grand jury secrecy rules, their delivery caps off an extraordinary 17-month quest by the former President and his lawyers to block investigators from obtaining the records.
New York District Attorney Cy Vance is investigating whether Trump and the Trump Organization engaged in tax fraud, insurance fraud and other schemes to defraud, including potentially providing false information to financial institutions or banks about the value of certain buildings and assets.
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With the records now in hand, Vance and his fellow prosecutors will be able to dig deeper into investigative theories, pursue interviews with key witnesses, and determine whether they believe any state laws have been violated.
"Our office obtained the records on Monday," said Vance spokesman Danny Frost.
Mazars' spokesman didn't respond to a request for comment.
The records may be critical to the investigation because they are likely to contain documents that reflect the decision-making behind valuations and tax write-offs, which may be important to determine whether there was intent to commit a crime. The investigators have wanted to review the documents before calling key witnesses before the grand jury, people familiar with the inquiry said.
In addition to the records from Mazars, Vance's office has been seeking a slew of other documents. They subpoenaed records and interviewed employees at Deutsche Bank, one of Trump's creditors, about loans given to him, and insurance broker Aon, according to multiple sources familiar with the investigation. Deutsche Bank has loaned Trump more than $300 million.
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Prosecutors have also subpoenaed Ladder Capital, which has loaned the Trump Organization over $100 million, and the Trump Organization for records relating to fees paid to consultants, including Ivanka Trump, these people said.
This has been updated with a statement from Vance's office.