London's best-loved monument suffers a 'sleight of hand' trick. MSN correspondent Justin Thyme reports.

Tuesday November 19: Chaos and confusion reigned in central London today as commuters in Westminster found themselves witnesses to an extraordinary and disturbing event.

At eight minutes past eight this morning the clock face of Big Ben - the capital's most recognised symbol - underwent a startling and sudden transformation.

The moment is best left to John Bateman, a parliamentary clerk who was on his way to work at the time, to describe: "There I was on my way to work at the time when I looked up at Big Ben to check whether I would be early or late for my first meeting of the day. As usual I saw I had eight minutes to get to my office for the eight o'clock daily briefing. But then I happened to glance up at the clock face for a second time - I couldn't believe my eyes. The numbers had all changed. No more I, II, III, IV, V and so on - just eights all the way round. I'd never seen anything like it."

Other eye-witnesses reported glimpsing a fast-moving colourful winged creature in the vicinity moments earlier.

MSN reporters tried to contact the office of Ken Livingstone to see if the London Mayor had any comment but could not get through. Nor was any comment forthcoming from the Prime Minister's Office. A spokesperson for the Society of London Heritage commented that although this wasn't a usual occurrence there should be no cause for alarm.

Some experts, however, aren't convinced. Reginald Weightman, Professor of Paranormal Psychology at the University of Ashby-de-la-Zouch in Leicestershire, believes that this marks the start of something big. "For the past eight years I've been researching what are known as 'Postchrysalide octo-events'. While a number of incidents were recently reported in America no physical proof has ever been offered - until now. This is the first occurrence that has been seen by so many people and recorded by the media. I'm certain we are seeing the start of something big, very big. It's not a one-off; it's a phenomenon."

Professor Weightman suggests that internet users in particular could be affected most by future outbreaks. He cites web surfers who are vulnerable to virus attacks as an example.

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