NEW YORK ( TheStreet) -- Shares of snack products company Diamond Foods ( DMND) dropped more than 20% Monday after the company said an investigation by its audit committee won't be completed until February, which will delay its 10-Q filing.

The Pop Secret popcorn and Emerald nuts manufacturer said it would file its 10-Q for its fiscal first quarter as soon as it could following the completion of the investigation. Though Diamond Foods said it anticipates receiving a note of deficiency from Nasdaq's listing qualifications department for not being compliant, Diamond Foods' stock will continue to trade on the exchange.

Diamond Foods' problems began when a former director, Joseph Silveira , died in November, possibly by suicide, amid accounting issues. The company also said in November that it would close the Pringles acquisition from Procter & Gamble ( PG) later than December because its audit committee received some questions about accounting for walnut grower crop payments. The Pringles deal is slated to close in the first half of fiscal year 2012.

The stock is off $9.66, or 23.8%, to $30.90.

-- Written by Alexandra Zendrian

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