UK intelligence officials planned a propaganda campaign against extremists by using the internet to infiltrate radical groups, a report claims.
Plans were mooted to use the internet to get to extremists
A Foreign Office letter, leaked to the Observer newspaper, reveals plans to spread anti-Western messages to gain the trust of Islamist radicals.
Dated 23 April 2004, it suggests spies pose as radicals to stop them taking up arms and to disrupt terror activities.
The Foreign Office said it did not comment on alleged leaked documents.
According to the Observer, the document reveals the security service was also looking at similar techniques used in Saudi Arabia and Egypt and was considering "exporting" them.
The confidential letter was from the Foreign Office's top intelligence official, William Ehrman, to the government's security and intelligence co-ordinator, Sir David Omand.
In it, Mr Ehrman is reported as suggesting that diplomats should continue to promote "messages that will bolster modern Western-orientated currents of thought in Islam".
The newspaper says he proposed developing "messages aimed at more radicalised constituencies who are potential recruits to terrorism" behind the scenes.
These radicals would not listen to the traditional calls "for the Middle East to become a zone of peace and prosperity", he wrote.
"They might, however, listen to religious arguments about the nature of jihad, that, while anti-Western, eschew terrorism. The latter may be a more appropriate sphere for information operations."
His only concern is reported to have been that similar operations used during the Cold War "had a mixed record" and that he might not have the experts needed for such an operation.