A former professional racecar driver was sentenced Friday to more than a decade behind bars after being convicted in October of running a payday loan business that reportedly scammed millions of people.

Scott Tucker, 55, was sentenced to 16 years and eight months in prison, to begin immediately, for what U.S. District Judge P. Kevin Castel called a scam “to extract money from people in desperate circumstances.”

Castel said a “staggering” 1 percent of the entire U.S. population suffered over the course of 15 years as a result of Tucker’s business, which he added was “a fraud from the beginning.”

Timothy Muir, 46, the general counsel for the company, was sentenced to seven years in prison for his conviction in the same trial.

According to prosecutors, the men’s loan operation employed more than 1,500 people and charged interest rates ranging from 600 percent to over 1,000 percent, generating more than $3.5 billion in revenue from 2008 to mid-2013 alone.

They did business as Ameriloan, Cash Advance, OneClickCash, Preferred Cash Loans, United Cash Loans, US FastCash, 500 FastCash, Advantage Cash Services and Star Cash Processing.

"For more than 15 years, Scott Tucker and Timothy Muir made billions of dollars exploiting struggling, everyday Americans through payday loans carrying interest rates as high as 1,000 percent," Acting Deputy U.S. Attorney Joan Loughnane said. "And to hide their criminal scheme, they tried to claim their business was owned and operated by Native American tribes."

The business ran from at least 1997 through 2013 but is now closed, Loughnane said.

According to the government, loans were issued to more than 4.5 million struggling people in all 50 states.

It said the jury saw evidence that many loans were issued in states, including New York, with laws that banned lending at the exorbitant interest rates Tucker charged and that the company provided scripts to its employees to read to individuals who complained that the loans were illegal.

Tucker, who hasn’t raced professionally in several years, penned a letter to the court, in which he said he was “remorseful.”

"I am remorseful, your honor, for having failed to accurately display, convey and live up to the vision I had,” he wrote. “I am remorseful, your honor, to have left a single person with the misperception that I do not recognize my responsibility to live as a good and fair business man, employer, and American citizen."

He also said the legal process had "taken its toll," leading his brother and business partner to commit suicide.

The Associated Press contributed to this report.