Uncertainty surrounds global security software provider Symantec following an official probe into its full year results.
The inquiry began after concerns were raised by a former employee. Symantec said it is conducting an internal investigation through its audit committee.
The company also said it may miss the deadline to file its annual 10-K report to the US Security and Exchange Commission, which has been notified of the situation.
Symantec may also have to restate some of its financial results, and its Q1/FY guidance. No other details about the potential problem have been released.
The news broke with Symantec's stock falling by a third as a result, wiping around $6bn off the firm's market value.
Ahead of the investigation being completed, Symantec said full year GAAP revenue was up 21% year-on-year to $4.8bn, with net income hitting $1.2bn. In the previous year, Symantec made a net loss of $106m after acquisition and restructuring costs.
Martin Courtney, an analyst at TechMarketView, said: "Symantec appears keen to follow the right course of action but the probe will take time.
"What happens next will have a significant impact on Symantec's business and reputation."