is an ex-MI5
(British Security Service
) employee turned whistleblower
He revealed details of a plot by the Secret Intelligence Service (MI6) to assassinate Colonel Mohmar Ghaddafi of Libya to the British newspaper The Daily Mail in August 1997.
In February 2000 he claimed former Beatle the late John Lennon funded the Irish Republican Army (IRA).
He spent over a year in exile in France with his girlfriend (also an employee of MI5) Annie Machon, before being extradited to the UK to face charges relating to breaches of the Official Secrets Act.
In March 2002 the House of Lords rejected his claim that the Official Secrets Act breached his human rights with regard to freedom of expression.
He will face trial at The Old Bailey later this year.
David Shayler was found guilty on three charges of breaking the Official Secrets Act and was sentenced to 6 months in prison. The trial judge Mr Justice Moses said to Shayler:
"Your own actions demonstrate a lack of any real insight into what you were doing or any intelligent foresight into its consequences.
"It is, contrary to your own belief, that blinkered arrogance which has led you here today."