IT SAYS its members brought about the conviction of radical Egyptian-born cleric Abu Hamza al-Masri, uncovered insurgent tactics in Iraq and are now working to provide intelligence from North Korea.
The organisation is not the US Central Intelligence Agency or Britain's MI6 but Vigil, a shadowy network of retired spies, senior military personnel, anti-terrorism specialists and banking experts.
The group's director Dominic Whiteman said he set up Vigil with two other businessmen last year to act as an conduit between retired spies who were still party to good, raw intelligence, and the police and security services.
"This evidence was just getting lost in the system," Mr Whiteman said.
Vigil numbers more than 30 members, from India to the United States.
Sixty per cent of Vigil's work involves gaining information via the internet, by infiltrating chatrooms.
The information gleaned is passed on to authorities such as the FBI, and British Counter Terrorism Command (CTC).
A CTC spokeswoman said: "The CTC is working closely with Vigil and in particular its director and spokesman who has made officers aware of chatroom material," she said.
One member of Vigil is credited with helping bring about the conviction of cleric Hamza, jailed in London in February for inciting racial hatred and soliciting murder, and wanted in the US on terrorism charges.
Glen Jenvey said he tricked Hamza into handing over videos and audio tapes which were used by US authorities in their case against James Ujaama, who pleaded guilty in 2004 to trying to help al-Qaeda militants.
Mr Jenvey's latest work has involved another hardline Muslim cleric, Omar Bakri Mohammed, banned from Britain in August as part of a crackdown on so-called "preachers of hate".
The revelation that Bakri had been delivering nightly sermons via an internet chatroom from his exile in Lebanon was reported by the BBC this week.
"When you listen to a whole lecture ... he's inciting terrorism, and supporting terrorism," Mr Jenvey said.
Anjem Choudary, a close friend of Bakri, denied there was anything sinister about the sermons and said the talks in "no way encourage or incite" British Muslims.
Mr Whiteman said a very trusted contact who had a "key security role in the UK" had revealed that 70 per cent of information given in a daily briefing to the US president, George Bush, by the intelligence chief John Negroponte centred on the British capital.
Vigil has now turned its sights on two groups prominent in Britain: Tablighi Jamaat, a missionary organisation that is planning to build Britain's largest mosque in east London, and Hizb ut-Tahrir (HT), an organisation Britain announced it would ban after the 7 July , 2005 London bomb attacks.
Both groups say they do not have links to militants and that they promote peace.
"We wanted to find out more," Mr Whiteman said, adding that his group had infiltrated the organisations. "There's nothing to suggest they will be banned, but there are definitely a few rotten apples that need to be looked at."