Meg Whitman has accused Autonomy of a 'wilful effort to mislead'. Photograph: ChinaFotoPress via Getty Images

Meg Whitman

The 56-year-old New Yorker, whose CV includes stints at Walt Disney, Procter & Gamble and Hasbro built her reputation at eBay, growing the business from 30 staff in 1998 to 15,000 10 years later – and became a billionaire in the process.

In 2010 Whitman campaigned unsuccessfully to become governor of California, spending £140m of her own cash.

Joined HP as president and chief executive, after a stint on the board, on a salary of just $1 a year – but was also awarded $16m (£10.1m) of stock options last year and $372,598 in "other compensation", including use of the company aircraft.

On Tuesday she accused Autonomy of a "wilful effort to mislead".

Léo Apotheker

The multilingual German spent 22 years at business software group SAP, becoming chief executive in 2008. He resigned two years later when his contract was not renewed.

He joined HP a few months later and led the $10bn acquisition of Autonomy.

Apotheker was paid some $25m at HP, even though he was in charge for less than a year.

That included a $4m golden hello and $2.4m as a "separation agreement" when he departed. The shares fell 45% on his watch, with an especially big dip coming after the Autonomy deal was announced. On Tuesday he said he was "stunned and disappointed" to learn of Autonomy's alleged accounting irregularities.

Mike Lynch

The king of the UK's "Silicon Fen" in Cambridge, Lynch has been described as Britain's answer to Bill Gates. He is also a director of the BBC and a science and technology adviser to David Cameron.

A Cambridge graduate, Lynch, 47, started several tech companies before founding Autonomy in 1996 and led a series of acquisitions before selling the business to HP in October last year. When he was asked to leave the business in May, he claimed it was too bureaucratic.

On Tuesday 47-year-old Lynch, whose fortune is estimated at around £500m, said he was shocked at the HP allegations, which he "flatly denies".

Larry Ellison

A month after HP's deal with Autonomy was agreed, Oracle founder Ellison told analysts that Mike Lynch had tried to sell Autonomy to him.

When Lynch denied the claims Ellison published the slides from a presentation it claimed Lynch had given at Oracle's head office and issued a press release titled: "Another whopper from Autonomy CEO Mike Lynch."

Oracle said they weren't buyers because even at $6bn – Autonomy's stockmarket value at the time – it was overvalued.

Frank Quattrone

Dot.com banker extraordinaire who took a huge number of tech companies to the stockmarket, including Cisco and Amazon, and earned more than $120m a year in the boom.

The 57-year-old was tried twice for obstruction of justice following an email he sent telling colleagues it was "time to clean up those files", but eventually the charges were dismissed. He then started a new advisory business, Qatalyst, selling such businesses as Motorola Mobility to Google and Autonomy to HP.

Oracle claimed Quattrone was with Lynch when they tried to sell Autonomy to them.