A former tax court judge and her husband have been indicted on federal charges for conspiring to commit tax evasion and obstructing the Internal Revenue Service's audit of the couple.

Diane Kroupa, 60, and Robert Fackler, 62, of Minnetonka, Minn., were each charged with conspiracy, tax evasion, filing false tax returns and obstruction of an IRS audit. The prosecution alleged they purposely understated their taxable income by approximately $1 million from 2004 to 2010, according to the Department of Justice.

"The allegations in this indictment are deeply disturbing," U.S. Attorney Andrew Luger said in a statement Monday. "The tax laws of this county apply to everyone, and those of us appointed to federal positions must hold ourselves to an even higher standard."

Kroupa, who was appointed to the U.S. Tax Court from 2003 to 2014, engaged in tax fraud during her tenure as a judge. The couple used Fackler's status as a self-employed lobbyist to claim more than $400,000 in bogus personal expenses, including trips to Alaska, Australia, the Bahamas, China, England, Greece, Hawaii, Mexico and Thailand.

Kroupa and Fackler are scheduled to appear in U.S. District Court in Minneapolis later this week.