The daughter of a university lecturer, Katharine Gun was thrust into the limelight after being accused of leaking top secret information.
Katharine Gun was sacked from her job as translator
The 29-year-old from the Regency Cotswold town of Cheltenham was a little-known translator working at the government's communications headquarters GCHQ.
But in March last year she was arrested, accused of breaching the Official Secrets Act by leaking an e-mail to the Observer newspaper from US spies asking British counterparts to tap the telephones of UN Security Council members.
In June 2003 she was sacked from her post.
She always admitted leaking the e-mail but argued she had "only ever followed her conscience" to prevent an "illegal war against Iraq".
The revelations contained in the leaked memo made her a cause celebre in the US.
'Role in democracy'
Actor Sean Penn and civil rights activist the Reverend Jesse Jackson were among the American celebrities who lined up to support her stance.
Five members of the US Congress also released an open letter to Tony Blair backing her actions.
Their statement read: "The British and American people deserved to know all the elements involved in the build-up to war. Whistleblowers play an essential role in a democracy."
Ms Gun, who grew up in Taiwan and is a fluent Mandarin speaker, denied the charge and could have been sentenced to a two-year jail sentence if she had been convicted.
But after she made her not guilty plea, the prosecution said that no evidence would be offered against her.
The 31 January memo reportedly said the US monitoring body, the National Security Agency had begun a "surge" in eavesdropping on UN Security Council countries about to vote on action in Iraq.
The author of the memo was supposedly Frank Koza, Defence Chief of Staff (Regional Targets) at the agency.
The Observer ran an article in March claiming GCHQ had been asked to help spy on the six countries key to the passing of a second UN resolution on Iraq.
Officials from Angola, Cameroon, Chile, Bulgaria, Guinea and Pakistan all had their phones tapped in what the Observer described as a "dirty tricks" operation.
At the time of Ms Gun said in a statement: "Any disclosures that may have been made were justified... because they exposed serious illegality and wrongdoing on the part of the US government who attempted to subvert our own security services; and to prevent wide-scale death and casualties among ordinary Iraqi people and UK forces in the course of an illegal war."
The interpreter's mother, Jan Harwood, said she is "deeply proud" of her daughter's actions which had revealed government "wrong-doing".
Her father Paul Harwood is a lecturer in European literature at Taiwan's Tunghai University.
His married daughter was educated in Taiwan before moving to Eastbourne, East Sussex, to study A-levels.
She went on to read modern Chinese with Japanese at Durham University where she was described as a bright, capable, "lively" student who would always speak out if she had something to say.
She was represented in court by civil rights group Liberty.
Its spokesman, Barry Hugill, said Ms Gunn's case "was a clear act of conscience.
"She didn't endanger anyone's life and she didn't put national security at risk."