A civil servant was cleared yesterday of breaching the Official Secrets Act after he leaked documents about the Government's involvement with radical Islamists.

The case against Derek Pasquill, an official in the Foreign and Commonwealth Office (FCO), collapsed after evidence emerged that the leaks were not considered damaging.

The decision was hailed as a "spectacular'' victory for the freedom of the press.

Mr Pasquill, 48, was accused of handing over information to a journalist about policy on two radical groups. Other leaks indicated worries in the Foreign Office about the radicalising effect of the war in Iraq on young Britons and the true extent of knowledge on "extraordinary rendition'' of terror suspects through Britain by the US.

The information, passed to Martin Bright, was published in a series of articles in The Observer and New Statesman between August 2005 and February 2006.

Prosecutors claimed that Mr Pasquill, a desk officer at the FCO, committed "a significant breach of trust'' by leaking "numerous documents of a harmful nature, containing material which would affect the UK's international relations''. But it emerged yesterday that minutes of discussions involving senior Foreign Office civil servants supported Mr Pasquill's defence that the leaks were not damaging.

Mark Ellison, prosecuting, told the Old Bailey, that there was no longer a realistic prospect of conviction and a decision had been taken to offer no evidence.

The decision will open the door for other whistleblowers to talk to journalists where there is evidence that their actions do not harm the Government.

The Recorder of London, Peter Beaumont, QC, ordered not guilty verdicts on all six counts against Mr Pasquill, from Notting Hill, west London. He had been facing a possible prison term.

After the case, Mr Pasquill said: "This has been a very unpleasant ordeal. Over a period of 20 months I have been arrested, suspended from my job, subject to a Special Branch investigation, on police bail and then charged. I am relieved that I have now been completely vindicated in my actions in exposing dangerous Government policy and changing its priorities.''

The Observer said in a statement: "We are delighted that the charges against Derek Pasquill have been dropped. He is an honourable civil servant who stood up for the best liberal values of his country.''

John Kampfner, the New Statesman editor, said: "This is a spectacular and astonishing victory for freedom of the press in the United Kingdom."

TI/Daily Telegraph, 10/01/08.