A man committed under the Minnesota's sex offender program since the mid-1990s has been sentenced to 10 years in prison for filing false federal income tax returns claiming refunds on behalf of others in the program totaling $550,000.

Arthur D. Senty-Haugen, 51, was sentenced Tuesday in federal court in Minneapolis after pleading guilty to conspiracy to defraud the government.

The IRS issued refunds on some of the returns, paying out $243,000 in all. Senty-Haugen's sentence puts him on the hook for that amount in restitution.

"Mr. Senty-Haugen's lengthy criminal history and flagrant disregard for the law and the criminal justice system was appropriately addressed by this significant prison sentence," U.S. Attorney Erica MacDonald said in a statement.

Senty-Haugen's attorney argued in a presentence filing for a prison term of about 6½ years, pointing to his "sense of hopelessness" because he is serving "perhaps lifetime commitment" in the Moose Lake sex offender program.

His commitment followed his conviction in 1993 in Ramsey County on eight counts of criminal sexual conduct involving several children.

Prosecutors countered in their own filing that Senty-Haugen "is an incorrigible, serial fraudster who appears to have engaged in numerous crimes simply to entertain himself" during his indefinite commitment, which began in 1994.

According to the defendant's guilty plea and court documents:

As part of the scheme that ran from early 2012 through late 2017, Senty-Haugen prepared and filed the false tax returns using the filers' names and Social Security numbers, as well as false wage and federal income tax withholding information.

Senty-Haugen recruited others not in the program to assist him in preparing and filing the fraudulent returns as well as collecting and transferring the illicit proceeds.

He admitted to filing 92 fraudulent income tax returns for tax years 2011 through 2016, seeking more than $550,000 in refunds to which the filers were not entitled.

Senty-Haugen directed that the proceeds be deposited into bank accounts that he owned or controlled.

The scheme was detected after Moose Lake staff told the IRS there were program participants who were receiving exorbitantly high federal income tax refunds.

In 2004, while confined in Moose Lake, Senty-Haugen was indicted in federal court for tax-fraud conspiracy for a similar but smaller scheme. He was convicted and sentenced to nearly six years in prison followed by three years' supervised release. Restitution was ordered in that case as well.

Senty-Haugen waited two days after that supervised release expired to start the fraud scheme that earned him his latest sentence.

In 2000 and 2013, Senty-Haugen was convicted in Carlton County District Court for opening credit accounts in the names of other people and businesses. He used those accounts to pile up debt of more than $40,000.