British tech entrepreneur Mike Lynch has been extradited to the US to face criminal charges over the £9billion sale of his firm Autonomy to Hewlett-Packard.
Mr Lynch - once dubbed "Britain's Bill Gates" after the Microsoft co-founder - will stand trial on charges including fraud, which he denies.
He is accused of overinflating the value of his software company when he sold it to HP in 2011.
The Home Office confirmed that Mr Lynch was extradited to America last Thursday.
The BBC says the 57-year-old businessman, who is a founding investor in the UK cyber-security firm Darktrace, has long fought attempts by US prosecutors to stand trial in America.
According to US court documents, Mr Lynch has been ordered to pay bail of £80million with authorities claiming he is a "serious risk of flight" following his years of fighting extradition.
Confined to address
He will be confined to an address in San Francisco, guarded by private security which he must pay for himself.
Mr Lynch's net worth is estimated to be around £1billion.
A court filing said: "After lengthy extradition proceedings in the United Kingdom, Defendant Michael Richard Lynch has finally landed on our shores to stand trial, accompanied by the United States Marshals Service."
Last month, Mr Lynch lost an appeal in the High Court arguing that he should instead be tried in the UK.
At the time of the sale, Autonomy was the UK's biggest software company and it was the largest-ever takeover of a British technology business.
HP was primarily known as a technology-hardware group and buying Autonomy was aimed at diversifying its business.
However, just a year later, HP wrote down the value of Autonomy by £7billion and claimed it had been duped into overpaying for the company.