Michael Cohen's stunning fall from the executive suite of the Trump Organization hit bottom Monday as he reported to a federal prison in New York to begin a three-year sentence.

"There is still much to be told," Cohen told reporters as he departed his apartment Monday morning, "and I look forward to the day when I can share the truth."

Once one of President Donald Trump's fiercest defenders, Cohen ultimately turned on his former boss,pleading guilty last year in part to arranging hush-money payments to women who claimed to have had affairs with Trump. The payments, Cohen said, were made at Trump's direction to protect the then-presidential candidate's campaign.

Cohen, who served as Trump's personal attorney and fixer, also pleaded guilty to income tax evasion, lying to Congress and bank fraud.

Cohen sentenced:Former Trump lawyer sentenced to three years in prison

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Blaming his misconduct largely on what he described as "blind loyalty" to Trump, Cohen was scheduled to report to the Federal Correctional Institution in Otisville, N.Y., a minimum security lock-up about 70 miles outside of New York City.

"I am proud of Michael Cohen’s courageous decision...to tell the truth about why Donald Trump represented a danger to our Constitution, our freedoms, and our nation’s fundamental values," Cohen attorney Lanny Davis said Monday.

Cohen is one of six former top aides to Trump to have been swept up in the recently completed investigation into Russian interference in the 2016 election. Among his offenses, the former Trump lawyer pleaded guilty to lying to Congress about Trump's pursuit of a tower project in Moscow during the 2016 campaign.

Earlier this month, former Trump campaign manager Paul Manafort was transferred to a Pennsylvania federal prison to begin a more than seven-year sentence for a host of financial fraud convictions related to his work in Ukraine on behalf of a Russia-back regime.