An internal investigation has turned up evidence of misconduct and accounting errors, Dell Inc. said Thursday.

The world's second-largest maker of personal computers said it would delay the filing of its annual report until its investigation is finished.

Dell's audit committee said it has turned up "a number of accounting errors, evidence of misconduct, and deficiencies in the financial control environment." Dell did not say what the alleged misconduct is or who might be involved.

"The audit committee is working with management and the company's independent auditors to determine whether the accounting errors necessitate any restatements of prior period financial statements, and to assess whether the control deficiencies constitute a material weakness in Dell's internal control over financial reporting," it said.

Last year, U.S. regulators launched a formal investigation of Dell's accounting. 

Dell shares fell 18 cents to $23.21 US in Friday trading on the Nasdaq.