A student caught in an FBI computer hacking "sting" has failed in a High Court bid to avoid extradition to the United States.

Pakistani national Usman Ahzaz came to Britain to study for a degree in information systems and computing.

The 24-year-old was arrested at the request of the US authorities and alleged to have "surreptitiously controlled" over 100,000 protected computers - a "botnet" - without the knowledge of their owners.

The court heard that, in 2010, an FBI undercover agent paid Ahzaz 600 US dollars in return for his agreement to surreptitiously install what he "believed to be malicious" computer code provided by the agent into the compromised computers.

Of the 100,000 computers involved, about 800 were physically located in the US.

Protected computers were defined in court to include computers used in interstate or foreign commerce or communication.

In March 2012, a Westminster Magistrates' Court judge sent the case to the Home Secretary, who ordered Ahzaz's extradition two months later on allegations relating to the 800 US computers.

If the allegations are proved, US law says his offence is punishable by imprisonment for more than 12 months.

Ahzaz appealed to London's High Court against extradition under the 2003 Extradition Act, his lawyers arguing the charges against him did not amount to an extradition offence.

But Lord Justice Gross, sitting with Mrs Justice Gloster, dismissed the appeal.

The judge said the focus of the extradition request was "an attempt rather than the causing of actual damage".

The natural inference was that the FBI agent had supplied software that was in fact innocuous, though Ahzaz believed it to be malicious.

But extradition was lawful because Ahzaz had unauthorised prior control of the computers in question without the knowledge or authorisation of their owners, and he had agreed to instal malicious software to impair the operation of the computers for reward, ruled the judge.

Mrs Justice Gloster agreed.