The UN itself admitted yesterday that it was surprised that the sect, whose formal name is the Watchtower Bible and Tract Society of New York, had been accepted on its list of non-governmental organisations for the last 10 years.

A former member said: "There is a glaring inconsistency which has emerged between the WTBTS's frequent portrayal of the UN as an evil organisation and its behind-the-scenes attempts to curry favour with that organisation. Were individual members to be aware of any formal link they would be devastated.

"By no stretch of the imagination could the WTBTS be considered to share the ideals of the UN charter unless you suppose that destruction of the UN by God is consistent with that charter."

The Witnesses, most frequently encountered by non-members when they attempt to make doorstep conversions, have faced accusations of bad faith before.

These have been most notably over the hierarchy's insistence that members should not accept blood transfusions and over accusations that sexual abuse of children by Witnesses' ministers in the US have been covered up.

Followers who criticise the Witnesses' leaders or question their decisions are routinely "disfellowshipped" which means fellow members including their families must shun them.

An obscure and ill-publicised decision by the hierarchy in New York last year modifying the prohibition on transfusions by deeming that God had revealed to them that transfusions of some blood components might be acceptable, providing there was later repentance, has come too late for many hundreds of followers known to have died because they refused blood.

In child abuse cases, the hierarchy insists there must be two independent witnesses - an almost impossible stipulation - before accusations are investigated.

The Watchtower Society has been denouncing the UN and its predecessor the League of Nations for 80 years, believing them to be a world empire of false religion, predicted in the Book of Revelation.

A recent publication since the organisation obtained its recognition describes the UN as "a disgusting thing in the sight of God and his people".

In an internal document, the WTBTS describes its policy as a "theocratic war strategy". It claims: "In time of spiritual warfare it is proper to misdirect the enemy by hiding the truth. It is done unselfishly; it does not harm anyone; on the contrary it does much good."

Being a recognised NGO with the United Nations - as more than 1,500 organisations are - gives status though not grants.

To qualify, organisations must show that they share the ideals of the charter, operate on a non-profit basis, "demonstrate interest in UN issues and proven ability to reach large or specialised audiences" and have the commitment and means to conduct effective information programmes about UN activities.

Disaffected Witnesses believe that the association, which has not been publicised to followers, is intended to increase the cult's respectability to sceptical governments, such as France's, which have refused to recognise it.

Paul Gillies, the Witnesses' spokesman in Britain, said: "We do not have hostile attitudes to governing bodies and if we are making representations on issues to the UN we will do so."

"There are good and bad bodies just as there are good and bad politicians. We believe what the Book of Revelation tells us but we do not actively try to change the political system."