A civil servant at the Foreign Office has been cleared of breaching the Official Secrets Act.
Derek Pasquill, 48, from west London, was accused at the Old Bailey of leaking confidential documents to the New Statesman and the Observer.
The papers were said to refer to secret CIA flights and the UK's contact with Muslim groups.
New Statesman editor John Kampfner described Mr Pasquill's prosecution as a "misguided and malicious move".
He said a number of government ministers had "privately acknowledged" that the information provided by Mr Pasquill had been "in the public interest and was responsible in large part for changing government policy for the good".