MINNEAPOLIS — The attorney for a former Stillwater mayor says his client will plead guilty to conspiracy to defraud the U.S. government.

The federal charges against Ken Harycki allege he knowingly prepared false tax forms to help the owners of health care companies conceal millions of dollars in tax liabilities. Defense attorney Thomas Brever tells Minnesota Public Radio News that Harycki has been cooperating with prosecutors and may receive a lighter sentence.

The Internal Revenue began investigating Harycki in October 2012. A federal search warrant affidavit says Harycki created shell companies for the owners and filed false tax returns on their behalf. IRS agents raided Harycki’s private accounting office in Stillwater in March.

Harycki is due in federal court Thursday. Sentencing guidelines call for 36 to 42 months in prison.