The estate of British technology tycoon Mike Lynch has been denied the right to appeal a High Court ruling that found it liable to pay Hewlett-Packard (HP) following the contentious acquisition of software firm Autonomy.

A High Court judge rejected the estate’s bid to challenge Mr Justice Hildyard’s 2022 decision, which concluded that HP had “substantially won” its more than a billion-dollar fraud claim against Mr Lynch over the 2011 purchase of Autonomy.

The estate had also sought permission to appeal against the judge’s subsequent ruling in July last year, which determined that Hewlett-Packard Enterprise (HPE) suffered losses totalling around £700 million as a result of the deal.

At a hearing in November, barristers for HP, now known as Hewlett-Packard Enterprise, said that Mr Lynch’s estate was liable to pay 1,786,668,553 dollars (£1.35 billion), which includes around 761 million dollars (£578 million) in interest.

In a ruling on Tuesday, Mr Justice Hildyard refused Mr Lynch’s estate permission to appeal against either of his earlier judgments, with a spokesperson for HPE claiming that it had been awarded damages and interest totalling around 1.24 billion dollars (£0.93 billion) from Mr Lynch’s estate.

The estate could still ask the Court of Appeal directly for the go-ahead to challenge the rulings.

HP sued Mr Lynch for around five billion dollars (£3.79 billion) following its purchase of Cambridge-based Autonomy for 11.1 billion dollars (£8.2 billion) in 2011.

The company claimed at a nine-month trial in 2019 – then believed to be the UK’s biggest civil fraud trial – that Mr Lynch inflated Autonomy’s revenues and “committed a deliberate fraud over a sustained period of time”.

It said this forced it to announce an 8.8 billion dollar (£6.5 billion) write-down of the firm’s worth just over a year after the acquisition.

In a ruling in 2022, Mr Justice Hildyard said the American firm had “substantially succeeded” in its claim, but that it was likely to receive “substantially less” than the amount it claimed in damages.

He said that Autonomy, founded by Mr Lynch, had not accurately portrayed its financial position during the purchase, but even if it had, HPE would still have bought the company, but at a reduced price.

Then in 2024, Mr Lynch died aged 59 along with his 18-year-old daughter, Hannah, and five others when his yacht, the Bayesian, sank off the coast of Sicily.

In written submissions for the hearing in November, Patrick Goodall KC, for HPE, said Mr Lynch had “not only perpetrated an enormous fraud, but lied about it at every stage”, and an appeal “aimed at escaping the consequences of that fraud” should not be allowed to be pursued.

Richard Hill KC, in written submissions for Mr Lynch’s estate, said the 761 million dollars (£578 million) in interest sought by the claimants was an “excessive sum … based on a flawed analysis”.

Mr Hill also said Mr Lynch’s estate should be allowed to appeal against the two earlier rulings, claiming that the judge “erred in law” and that there was a “compelling reason for allowing the appeal to be heard”.