Sushovan Hussain, who has been imprisoned in the US for his role in the fraudulent sale of Autonomy to ­Hewlett-Packard in 2011, has been allowed to cash in a stake valued at as much as $100m (£75m).

The 182,000 shares in ICP Darktrace, an arm of the venture capital fund Invoke, had been held by a US court as bail for more than a year as Hussain appealed against his fraud conviction.

The appeal failed and Hussain has been serving a five-year fraud sentence in a prison in Pennsylvania since October. Last month, the court released the shares, allowing him to sell them and pay off $10m in penalties owed as part of his conviction, according to US filings. US government lawyers had said his stake was worth up to $100m, though this had been disputed by his lawyers.

The sale comes as Darktrace, one of Britain’s top cybersecurity companies, prepares to go public in London.

Bankers considered for the float had reportedly raised concerns about whether they could take part in it due to Hussain’s investment in the company. Invoke, run by Autonomy’s former chief executive Mike Lynch, was Darktrace’s first investor and ICP Darktrace – the part of the fund that holds Invoke’s Darktrace shares – has a 39pc stake in the company, according to research website PitchBook.

It is unclear whether Hussain has been able to dispose of his entire stake or who may have purchased it. Dr Lynch had been named as the only ­possible buyer, Hussain’s legal team said last year, but a spokesman for Dr Lynch said he had not purchased them.

Dr Lynch has himself been charged with fraud by US authorities but is fighting extradition to America, with a hearing set to take place in the new year. He has denied any wrongdoing. Autonomy was one of Britain’s biggest tech companies before its $11bn sale to HP. The US giant wrote off most of the acquisition’s value the following year, and is suing Dr Lynch in the UK for $5bn.

• Darktrace PLC