A private housing company has filed a lawsuit against St. Clair County claiming a state law intended to force the company to pay millions of dollars in taxes is unconstitutional and should be struck down.

Hunt Development Group in El Paso, Texas, claims a state law amended in August to allow local taxation of privately-operated housing on Scott Air Force Base violates the U.S. Constitution and Illinois Constitution. The law added 1,228 homes to the county tax rolls -- increasing Hunt Development's annual tax bill by about $1.3 million and may force the company to pay at least $3.6 million in back taxes from the past six years.

County Administrator Dan Maher said the company has failed in other attempts to overturn the law, including appealing to the Illinois Department of Revenue.

"We feel the law is Constitutional," Maher said. "There have been numerous similar agreements all over the country (between private companies and taxing bodies)."

Representatives with Hunt Development did not return repeated requests for comment regarding the lawsuit.

The dispute stems from the company seeking exemption from taxation because the homes are built upon federal property at Scott Air Force Base. Federal property is exempt from local and state taxation, however, St. Clair County is taxing licenses related to the development.

Maher said he expects the company will pay taxes currently due following the outcome of the suit, and noted an escrow account has been established to hold the funds in the meantime.

The company seeks to stop the county from assessing the disputed property and levying a tax against the development on behalf of local taxing bodies, such as Mascoutah School District 19, townships and Southwestern Illinois College.

District 19 leaders were among those lobbying in favor of the law. School officials said it would prevent the district from raising property taxes on other residents to make up the loss of non-taxed privatized military housing.

The newly added property is valued at $64.4 million, according to the St. Clair County Assessor's Department, and District 19 would annually collect about $930,000 in taxes from the property.

Mascoutah School District Superintendent Craig Fiegel said the ongoing legal fight has kept the district from budgeting for the increased tax revenue.

"We aren't anticipating receiving revenues right now," Fiegel said. "It is about a million dollars a year though, which is a significant amount of lost revenue."

Fiegel said the district is concerned the reversal of the law could force it to repay nearly $5 million in previously collected taxes from the company.

Hunt claims the law is unconstitutional for multiple reasons. Most notable of which is it singles out licensees of the U.S. government for taxation while exempting all other Illinois licensees from taxation.

The lawsuit also claims the Illinois General Assembly overstepped its legislative power, and exercised powers reserved to the judiciary branch of government. In particular, the suit claims the state legislature determined what personal property is protected under the Illinois Constitution -- a power the Illinois Supreme Court exercised as recently as 2010.