Sources in Whitehall and at the UN in New York say MI6 first infiltrated the UN Weapons Inspectorate soon after it was set up in 1991.
"A number of officers were asked if they were interested in the posting. One officer joined for a period," said a source. Some officers are thought to have been rotated through the teams.
Norman Baker, a Liberal Democrat MP, has put down a series of questions for Robin Cook, the Foreign Secretary, and the Defence Secretary, George Robertson, due to be answered today, on whether British intelligence officers were involved in Unscom.
He said last night: "I would be very, very angry if the independence and integrity of the Unscom was compromised in this way. To include MI6 and Ministry of Defence intelligence staff deliberately in the UN teams is to undermine the UN itself."
Unscom teams were recruited from many states, usually chosen for a specialisation in areas of nuclear, chemical and biological warfare and communications.
The inspectors found that Iraq had a far more elaborate concealment system than had been supposed.
Unscom decided it needed to break the Iraqi wall of secrecy and turned to the intelligence communities of several countries, notably the US, Britain and Israel. They supplied Unscom with experts in espionage - that is, spies.
Earlier this month some American newspapers, citing anonymous US officials, reported that intelligence ostensibly gleaned by the weapons inspectors had been passed to Washington for its own use. Some of the information, they said, had been used to identify targets in last month's British and American attacks on Iraq.
Most controversial have been reports that the US supplied Unscom with an eavesdropping device to tap Iraqi officers' communications. Sources say the US demanded overall control of the machine and made sure all data received was shown only to experts from a narrow club of states. Explicitly barred were Israel, France and Russia. Those with full access reportedly came from just four countries: the US, Australia, New Zealand and Britain.
British Unscom members were recruited by the Foreign Office, which said: "We don't comment on intelligence matters." But The Independent has established that the British group included intelligence officers, using diplomatic cover to gather intelligence independently.
Asked by The Independent for a list of British inspectors, the Foreign Office and Unscom both refused.
"We do not have the staff available to compile such a list," said the Unscom spokesman, Euan Dungannon, in New York. A Foreign Office spokesman said: "We do not have such a list."
A US F-15 fighter attacked an Iraqi missile installation in the northern no-fly zone yesterday. A Pentagon spokesman said the F-15 fired in self-defence after aircraft enforcing the no-fly zone were tracked by Iraqi radar. There was no damage to US aircraft, he said.Reuse content