The controversy surrounding allegations of accounting fraud at Autonomy have deepened after Hewlett-Packard said the US Department of Justice is investigating the matter.

HP also detailed several class action lawsuits against it in relation to the company’s acquisition of Autonomy.

HP, which bought Autonomy for $11 billion last year, was plunged into an accounting scandal last November over its acquisition of the software maker, after writing down the value of the deal by $8.8 billion.

The struggling US technology group alleged that “serious” accounting improprieties at Autonomy were responsible for more than $5 billion of the writedown. Autonomy founder Mike Lynch has denied the allegations.

– Copyright 2012 The Financial Times Ltd