LONDON — Britain's government says an English computer hacker won't be extradited to the United States, ending his decade-long campaign to avoid trial there over allegations he broke into sensitive military and NASA computer networks.

Home Secretary Theresa May told the House of Commons on Tuesday that she had refused the U.S. request to send Gary McKinnon to face charges over an electronic rampage between 2001 and 2002. One prosecutor had accused him of carrying out "the biggest hack of military computers ever."

The 46-year-old claimed he had accessed the 97 U.S. government computers to hunt for evidence of extraterrestrial life.

May blocked his extradition after being told there were concerns over McKinnon's mental health, and a risk he could attempt to commit suicide.