New York prosecutors are set to review eight years of Trump’s tax returns.

The United States Supreme Court on Monday cleared the way for the Manhattan district attorney to obtain eight years of federal income tax returns of former President Donald J. Trump and other records from his accountants. The decision capped a long-running legal battle over prosecutors’ access to the information.

Whether prosecutors find evidence of crimes, however, will also depend on other information not found in the actual returns.

The bioreports last year provided a preview of what awaits the district attorney, Cyrus R. Vance Jr., when it obtained and analyzed decades of income tax data for Mr. Trump and his companies. The tax records provide an unprecedented and highly detailed look at the byzantine world of Mr. Trump’s finances, which for years he has simultaneously bragged about and sought to keep secret.

The Times’s examination showed that the former president reported hundreds of millions of dollars in business losses, went years without paying federal income taxes and faces an Internal Revenue Service audit of a $72.9 million tax refund he claimed a decade ago.

Among other things, the records revealed that Mr. Trump had paid just $750 in federal income taxes in his first year as president and no income taxes at all in 10 of the previous 15 years. They also showed he had written off $26 million in “consulting fees” as a business expense between 2010 and 2018, some of which appear to have been paid to his older daughter, Ivanka Trump, while she was a salaried employee of the Trump Organization.

The legitimacy of the fees, which reduced Mr. Trump’s taxable income, has since become a subject of Mr. Vance’s investigation, as well as a separate civil inquiry by Letitia James, the New York attorney general. Ms. James and Mr. Vance are Democrats, and Mr. Trump has sought to portray the multiple inquiries as politically motivated, while denying any wrongdoing.