Italian news reports Monday say prosecutors are accusing the founder of the Parmalat food company of misappropriating about $1 billion.
Parmalat's founder, Calisto Tanzi, was detained by police on Saturday and is being questioned for alleged fraud and lying to regulators.
Mr. Tanzi was taken into custody after reports that billions of dollars listed on the company's books could not be found.
Mr. Tanzi is among 20 people under investigation including current and former Parmalat executives and auditors.
Milan's stock market suspended trading in Parmalat shares Monday after the huge food company was declared insolvent on Saturday.
The accounting scandal has pushed the value of Parmalat's shares down by 90 percent.
The Italian company employs 36,000 people in two dozen countries around the world, selling more than $9 billion worth of milk, yogurt, juice and other food products.