NASA hacker Gary McKinnion is launching another legal battle in a bid to avoid extradition to the US.

In 2001, McKinnon broke into US military computers, including those belonging to NASA, in a bid to prove the US government had knowledge of UFOs.

While he says his actions caused no damage, the US claims he stole 950 passwords, deleted files at a naval base in New Jersey and rendered the military computer networks used following September 11 useless. The US estimates the damage caused by McKinnon at $700,000 (£433,000).

In August 2008, the European Court of Human Rights agreed to allow McKinnon to be extradited to the US. In a bid to avoid extradition McKinnion told the British Crown Prosecution Service (CPS)  said he would plead guilty if tried in the UK. However in February this year, the CPS refused to bring charges against McKinnion.

A judicial review of the original decision to extradite McKinnion, who suffers from Asperger's Syndrome, will take place this week. McKinnion's lawyers are expected to reveal that he will be at risk of psychosis or suicide if he is removed from the UK.