The Church of Scientology unveiled its new London headquarters today with a grand opening ceremony.

The religion, which counts Hollywood stars Tom Cruise and John Travolta among its followers, is expanding its British operation.

It has bought and refurbished the former home of the British and Foreign Bible Society, latterly the offices of BP, for its new HQ.

The five-storey Victorian building in the City of London is a stone's throw from St Paul's Cathedral and stands next door to an Anglican church, from where parishioners emerged after their Sunday service to watch the proceedings with some bemusement.

Several hundred Scientologists, including church dignitaries and assorted VIPs, braved the driving rain for the outdoor ceremony.

They listened to an address by Scientology leader David Miscavige, whose arrival was greeted with whoops and cheers from the crowd.

Mr Miscavige described the occasion as "momentous".

Scientology founder L Ron Hubbard chose London as home to the organisation's first offices.

Mr Miscavige said: "This day will go down in history. Of all the foreign lands where LRH lived and worked, he called England home.

"This is the city wherein he first defined the human spirit as an immortal being possessed of capabilities beyond anything predicted and so arrived at the axiomatic truths on which the whole of Scientology is founded."

Other speakers at the event included United Nations peace envoy Dr Iftikhar Ahmed Ayaz, who praised the faith and told the crowd: "It is my personal belief that this church can restore what this world has lately lost."

Kevin Hurley, divisional commander of the local Snow Hill police station welcomed the church to the City and said its members were "raising the spiritual wealth of society".

The ceremony began with a procession by the London Scottish Regimental Pipe and Drum Band and ended with an explosion of red, white and blue tickertape.

Afterwards the public were invited inside to discover more about the work of the Scientologists.

One room is devoted to the accomplishments of Hubbard - described as an explorer, writer, naval officer, humanitarian, artist and philosopher.

Video screens and exhibitions explain the various Scientology programmes, which include anti-drugs courses and a campaign against the perceived evils of psychiatry.

Among the guests who did attend was Hollywood actress Anne Archer, whose roles include Michael Douglas's wife in Fatal Attraction.

Archer was raised a Christian Scientist but joined the Church of Scientology in 1976 and credits it with turning her life around.

She said: "I met some people who I observed to be very sane and who said some very interesting things. I later found out they were Scientologists.

"At that time I had some problems in my life and I went for my first auditing.

"The change was so remarkable and so quick. I went from feeling utter despair to positivity within two weeks."

Archer conceded that Scientology has received a bad press but said: "All new ideas are criticised but we are doing remarkable things."