ORLANDO, Fla. — A federal judge in Orlando on Wednesday sentenced a Lake County, Florida man to three years in prison for obstructing an IRS effort to collect his unpaid income taxes.

Dennis J. Nagle, 67, of Clermont refused to pay federal income taxes since 1999 and employed a complicated scheme to hide himself and his property, according to prosecutors with the U.S. Attorney’s Office for the Middle District of Florida.

Nagle, who holds a chemical engineering degree, claimed he was exempt from taxation. He owed the IRS more than $400,000 by 2014.

It took the IRS “months, if not years,” to untangle his multi-state, mail-forwarding scheme to avoid contact with agents, prosecutors said.

“He literally sent the IRS running all over the country,’’ an attorney for the government said on the first day of Nagle’s trial.

He held executive-level positions with six-figure salaries, prosecutors said. At one point, he was a vice president of a company called Nutraceuticals, managing the payroll for the manufacturer of nutritional supplements.

Nevertheless, Nagle ran a “corrupt crusade” and a “mean-spirited campaign” to cheat the government, prosecutors wrote.

“The defendant has largely lived a privileged life,” prosecutors wrote. “He has a college education, has held numerous high-paying jobs, and has a supportive wife. He is also in good physical and mental health.”

A federal jury in Orlando on January 30 convicted Nagle of corruptly obstructing the due administration of the internal revenue laws, records show.

U.S. District Judge Paul G. Byron sentenced Nagle on Wednesday and ordered him to pay $221,502 in restitution to the federal government.

Byron also sentenced Nagle to one year of supervised release after prison.

The judge’s prison sentence, the maximum allowed under the law, matched the punishment requested by federal prosecutors.

“The defendant’s crime is serious,” prosecutors argued in a June 19 sentencing memo. “For more than 10 years, he waged a multifaceted attack against the tax laws of the United States. 

"Over that period, the defendant had numerous opportunities to pay his taxes, but he intentionally refused to do so.”

An independent arm of the IRS called the National Taxpayer Advocate estimates $381 billion in income taxes are not collected annually because of tax evaders. The advocate “calculated that there is a surtax of more than $3,000 for each honest taxpayer to subsidize noncompliance by others,” the memo said.

In a court appearance after he was indicted, Nagle said he didn’t recognize the authority of the federal court.

The IRS attempted to collect Nagle’s unpaid taxes by filing liens and garnishing his paychecks and pension.

In response, Nagle submitted false forms to his employer claiming he was exempt from federal taxes, records show.

He attempted to pay off his tax debts with checks written on a closed bank account, and threatened to file criminal complaints against IRS collection officers, according to prosecutors.

In all, Nagle sent the IRS at least 15 worthless payments, purportedly totaling more than $1.9 million.

Nagle is being held at the Orange County Jail as a federal inmate. He will be handed over to the Bureau of Prisons to serve his sentence.