Autonomy founder Mike Lynch is leaving the company after less than a year under the ownership of HP.
The news came as HP announced 27,000 redundancies last night, as part of its quarterly financial results.
HP bought Autonomy for $10.3 billion (£6.7 billion) last October, with Lynch earning £500 million from the sale. HP's CEO Meg Whitman said that Autonomy had suffered disappointing licensing revenues in the second quarter, "with a significant decline year-over-year, according to TechMarketView analyst Richard Holway.
Whitman cited the difficulties of growing an entrepreneurial company as the reason for the decline.
"It is not the product. It's not the market. It's not the competition. This is classic entrepreneurial company scaling challenges - it's a whole different ball game," she said.
However, according to sources close to the situation, the entire management team and 20 percent of all Autonomy's staff have left since the HP takeover.
These include president Sushovan Hussein, chief financial officer (CFO) Steve Chamberlain, chief technology officer (CTO) Pete Menell, chief marketing officer Nicole Eagan, chief operating officer Andy Kanter, and Martina King, head of Lynch's more recent pet project, the augmented reality platform Aurasma.
"They were finding it very hard to deliver on strategy because of the differences between the software and hardware business," a source said.
This contrasts with Lynch's comments last December in an interview with ComputerworldUK, when he said that Autonomy had not lost "one significant member of staff" through the acquisition.
Around the same time, Mike Lynch also told delegates at the Bloomberg Enterprise Technology Summit in London that HP had vowed not to interfere with the day-to-day style or workings of his business.
"HP understands the Autonomy is high-speed, smaller and more agile," he said at the time. "And that it needs to be left that way.
"They drove this acquisition in that style."
When the Autonomy acquisition was announced last summer, HP customers and shareholders reacted with bewilderment and sometimes fury to the US giant's wider plans to reinvent itself as a software company.
Autonomy shareholders didn't seem that enthusiastic about the deal either. Indeed, HP was forced to extend the deadline for the takeover bid to be accepted when fewer than half of shareholders voted in favour at the first closing date in September.
Commenting on Lynch's departure, TechMarketView's Holway said: "This is obviously bad news for Autonomy's people in Cambridge. In some respects it might be good news for Lynch and UK-based software development. We fully suspect Lynch will use his vast fortune to produce an Autonomy#2 - wherever that might lead. It would undoubtedly be Cambridge-based - Lynch's physical and emotional home.
"As for HP, we shed a tear for this once great company. The list of once great companies acquired by HP over the last decade only to disappear without trace adds yet another name."