Autonomy founder Mike Lynch has reignited his war of words with Hewlett-Packard boss Meg Whitman, publishing an open letter on the day of the computer company's annual meeting in which he accuses her of making "incendiary and defamatory" allegations.
Lynch has urged shareholders at the HP meeting in Santa Clara, California, to demand HP release calculations it used to make an $8.8bn (£5.3bn)writedown on the value of Autonomy in November 2012, a year after acquiring it for $11bn.
He writes: "In the 16 months that have followed, HP has not provided information or evidence to the Autonomy team to substantiate any allegation. Instead, it has selectively leaked documents and information to the international media, frequently using material taken out of context to create false impressions and smear our reputations."
Lynch also claims that HP's senior executives were aware of certain Autonomy sales practices months before it told shareholders a whistleblower had flagged them.
The letter also calls for HP to release valuation reports prepared by its advisers, which he claims confirm HP paid a fair price for his business.
"HP's independent advisers carried out several valuation reports of Autonomy after the acquisition, which explicitly included Autonomy's hardware sales and confirmed the value of the company at $11bn? Does HP management deny this? Will they disclose these reports to shareholders?"
Lynch has repeatedly denied wrongdoing. Feted as Britain's most successful software entrepreneur when he sold his company in 2011, he is now fighting to save his reputation.
His letter states: "Meg Whitman has made incendiary and defamatory accusations on behalf of her company. She should now present the detailed evidence that justifies those allegations."
HP responded with a statement, saying: "As HP has previously reported, it uncovered numerous accounting irregularities at Autonomy prior to its acquisition by HP. HP reported those irregularities to appropriate civil and criminal regulators in the US and UK. HP continues to cooperate in ongoing investigations by those regulators."