NASA hacker Gary McKinnon will face no legal action in the UK.
The Crown Prosecution Service (CPS) has decided the appropriate jurisdiction for the McKinnon case to be heard is the US, after discussing the case with US Department of Justice and the police.
According to Karen Todner, McKinnon's solicitor, the decision on Friday is an "interesting" one given that he was first arrested and questioned by UK police.
"Mr McKinnon has always indicated that he would be willing to plead guilty to an offence under the Misuse of Computers Act but clearly cannot do so if he is not going to be prosecuted," she said in a statement.
US authorities started their bid to extradite McKinnon in 2005, accusing him of causing hundreds of thousands of dollars of damage by hacking into NASA and military systems in 2002. McKinnon admitted to the intrusion, but claimed he was looking for evidence of UFO activity.
US requests for his extradition were formally turned down by the Home Secretary Theresa May in October on human rights grounds, after medical reports said McKinnon, who has Asperger's, would be a suicide risk if extradited.
The CPS remains convinced that the US is the appropriate place for any trial.
"None of the reasons for the original decision in 2002 that the appropriate place for Mr McKinnon to be tried was the United States have altered. So far as the evidence is concerned, the position in 2012 is the same as it was in 2002. Most of the witnesses are in the US, as is nearly all the physical evidence and the bulk of the unused material, some of which is sensitive," Keir Starmer QC, director of public prosecutions, and Mark Rowley, assistant commissioner of the Metropolitan Police Service, said in a joint statement.
"The potential difficulties in bringing a case in England and Wales now should not be underestimated" — CPS statement
"The potential difficulties in bringing a case in England and Wales now should not be underestimated, not least the passage of time, the logistics of transferring sensitive evidence prepared for a court in the US to London for trial, the participation of US Government witnesses in the trial and the need to fully comply with the duties of disclosure imposed on the CPS. The prospects of a conviction against Mr McKinnon, which reflects the full extent of his alleged criminality, are not high," they added.
While the CPS has today closed the book on the prospect of legal action against McKinnon on home soil, the US authorities have yet to come to a similar decision.
"Mr McKinnon's legal team remains aware that his extradition warrant is still outstanding and will seek to explore other ways in which Mr McKinnon can receive complete closure on this long saga," Todner said.