Software firm Autonomy founder Mike Lynch is defending the financial accounts of his company, which he sold to Hewlett-Packard (HP) for $11bn in 2011, after the investigations of US and UK authorities into accusations of accounting fraud.

According to the Irish Independent, HP confirmed that information from a whistleblower has been passed to the US Department of Justice, the Securities Exchange Commission (SEC), and Britain's Serious Fraud Office.

"On November 21, 2012, representatives of the US Department of Justice advised HP that they had opened an investigation relating to Autonomy," stated the US company in the filing.

"HP is co-operating with the three investigating agencies."

The Tipperary-born, UK-based Mike Lynch, previously dubbed "Europe's Bill Gates" because of this success, stayed with the company after the takeover but left in May this year. He defends his company's track record despite the accusations of accounting fraud under its former executives, including Lynch himself.

In November, HP wrote off $5bn from the $11n value of the company, accusing Autonomy's former management of accounting "improprieties," the Independent reports.

Said Lynch: "Simply put, these allegations are false, and in the absence of further detail we cannot understand what HP believes to be the basis for them."

"We continue to reject these allegations in the strongest possible terms. Autonomy's financial accounts were properly maintained in accordance with applicable regulations, fully audited by Deloitte and available to HP during the due-diligence process."

He added that he would cooperate with any investigation but has not been approached by the authorities to date.