According to an annual report filed Thursday by Hewlett-Packard (HPQ), the U.S. Department of Justice has officially opened an investigation into its allegations of accounting fraud at Autonomy, the British software maker it acquired for $11 billion last year.

In November, HP announced it had uncovered widespread accounting fraud at Autonomy, a discovery it said played a big role in the decision to write down $8 billion in the value of the company.

While HP had previously said it had submitted evidence to federal regulators, this is the first confirmation that an actual investigation is under way. According to the filing:

A HP Invent logo is pictured in front of Hewlett-Packard international offices in Meyrin near Geneva in this August 4, 2009, file photo. Hewlett-Packard Co
A HP Invent logo is pictured in front of Hewlett-Packard international offices in Meyrin near Geneva in this August 4, 2009, file photo. Hewlett-Packard Co said on November 20, 2012, it took an $8.8 billion charge related to its acquisition of software firm Autonomy, citing "serious accounting improprieties," as it swung to a fourth-quarter loss. REUTERS/Denis Balibouse/Files (DENIS BALIBOUSE)

"As a result of the findings of an ongoing investigation, HP has provided information to the U.K. Serious Fraud Office, the U.S. Department of Justice and the (Securities and Exchange Commission) related to the accounting improprieties, disclosure failures and misrepresentations at Autonomy that occurred prior to and in connection with HP's acquisition of Autonomy. On Nov. 21, 2012, representatives of the U.S. Department of Justice advised HP that they had opened an investigation relating to Autonomy. HP is cooperating with the three investigating agencies."