The British arm of global auditing firm Deloitte says it didn't know of improper or false accounting at Autonomy, a company Hewlett-Packard Co. bought and now accuses of cooking its books.

On Tuesday, HP said it would take a charge of more than $5 billion to reflect that the value of Autonomy was inflated by false accounting when HP bought it in October 2011 for $9.7 billion.

Deloitte UK was Autonomy's regular auditor. It "categorically denies" having any knowledge of Autonomy's alleged misrepresentations. Deloitte didn't provide due diligence services to HP for the deal. Instead, HP hired KPMG to review Autonomy's books. KPMG didn't find any problems, either.

Former Autonomy CEO Mike Lynch rejected HP's allegations on Tuesday, saying HP mismanaged the company after the acquisition.