The owner of a northeast Missouri trucking company and grain elevator faces 15 state and federal felony charges accusing her of operating a grain fraud scheme that prosecutors say could cost farmers up to $50 million.

Cathy M. Gieseker, 45, of Martinsburg, was charged Monday with 12 state felonies for stealing, unlawful merchandising practices and withholding records or filing false financial statements. The U.S. Attorney's office in St. Louis also on Monday revealed grand jury indictments from July 16 accusing Gieseker of felony mail fraud, wire fraud and interstate transportation of stolen property.

If convicted, she could face up to 120 years in prison on the state charges and 50 years on the federal charges.

Missouri Agriculture Director Jon Hagler said it appeared to be the biggest fraud scheme of its type in state history with about 180 victims scattered across Missouri. Most victims appeared to be in Audrain County in the northeast part of the state and the surrounding areas, state officials said.

Missouri Attorney General Chris Koster said Gieseker surrendered to federal authorities in St. Louis on Monday and would be turned over to the state. The attorney general's office filed its charges in Audrain County and plans to prosecute the case itself.

Gieseker's attorney, Travis Noble Jr., denied she was involved in fraud and said she plans to plead not guilty.

Gieseker surrendered herself to federal authorities in St. Louis on Monday and was released on bond. Noble said she also would be released on bond for the state charges.

Prosecutors are accusing Gieseker of operating a Ponzi scheme. In that type of scam, the perpetrator promises high investment returns and then uses money from new investors to cover profits promised to previous investors.

Federal prosecutors say Gieseker marketed grain from October 2002 through February 2009 through her company, T.J. Gieseker Farms and Trucking. She is accused of promising farmers that she had contracts with Archer Daniels Midland Co. and could provide returns of 50 percent to 100 percent more than market prices.

But prosecutors say Gieseker didn't have contracts with Archer Daniels Midland for above-market prices. She sold grain at spot prices, using proceeds from other grain sales to pay above-market prices to some farmers, they said.

Noble said Gieseker was promised a certain amount of money for the farmers' grain and she passed those profits to farmers. The money stopped flowing, he said, when Gieseker stopped receiving money.

Noble declined to say who promised to buy grain from Gieseker.

"I don't think there is a farmer out there prior to 2009 that Cathy Gieseker didn't pay the money that she promised," he said.

State and federal prosecutors estimated farmers lost at least $27 million in grain sales, but the U.S. Attorney's office said it could be as high as $50 million. It's unclear how much will be returned to farmers.

"I don't want to also give false hopes to people. A Ponzi scheme has a way of destroying resources that enter the Ponzi scheme - this is essentially what occurred here," Missouri Attorney General Chris Koster said.

Later, he said restitution was "unlikely."

That's because Gieseker has limited assets. She owns four parcels of land in Martinsburg, one property in Rush Hill and 22 vehicles, such as tractor-trailers and ATVs, according to federal authorities, who are trying to take over assets she earned through illegal activity.

The start of returning money to farmers caught up in the scheme is scheduled to begin during a public hearing at 10 a.m. on Aug. 7 at the Knights of Columbus hall in Martinsburg. A $297,000 business bond that Gieseker had with the state will be divvied up by an administrative hearing officer.

State regulators froze the assets and suspended the license of T.J. Gieseker Farms and Trucking in February after a Missouri Agriculture Department audit uncovered financial irregularities connected to the business.

The accusations in the Gieseker case show an "inadequacy of state oversight" of grain marketers, Koster said.

The case prompted several rural lawmakers in March to propose legislation that would have increased the minimum bonding requirements for licensed grain dealers and set criminal penalties for unlicensed dealers. It did not pass last session.

Lawmakers considered creating an indemnity fund for farmers who lose money in speculative commodity markets. Several states have such accounts, but Missouri lawmakers have thus far rejected the idea.