Parmalat said on Monday it had net debts of 14 billion euros ($17.6 billion) in September, almost eight times the figure given by the food group's former top managers, most of whom are now under arrest.
The numbers suggested bondholders may get back less than 10 percent on the value of their bonds, an investment banker said.
Auditors PriceWaterhouse Coopers (PWC), hired to check Parmalat's books after the scandal erupted in December, also found that sales and core earnings figures had been highly inflated, the insolvent multinational said in a statement.
The company's battered bonds lost more value after the announcement and its 6.125 percent euro bond due in 2010 bid three percentage points lower at 15.5 percent of face value.