Visitors have to shell out more at London's fee-paying sights, such as Buckingham Palace, the Tower of London and Madame Tussauds, than at similar attractions in other capitals, the survey said.

It examined the cost of visiting attractions in London and 10 other cities, including Paris, Sydney, Hong Kong, New York and Rome. The prices charged by nine of the most popular tourist attractions in each city were examined as well as the cost of an open-top bus ride.

A family of four would have to pay £549.30 (S$1,480) if they wanted to take part in all 10 activities in London, compared with £386 in Paris, £376 in New York and £216 in Rome, the survey found.

In some cases, the same company offering the same attraction in different cities charged wildly different entry fees.

For instance, a family of four visiting Madame Tussauds in London would have to pay £85, making it the most costly fee-paying attraction in the survey's list. Yet, the same family visiting the company's attractions in Hong Kong, New York and Berlin would pay only £27, £52 and £50.80, respectively.

It was the same story with bus tours. While the Original London Sightseeing Tour charges a family of four £65 to tour the capital in one of its open-top buses, the company's bus tours in Paris, Sydney, Dublin and Edinburgh charged anywhere between £24 and £56.

Although London's tourism chiefs frequently say that many attractions in the city, including some galleries and museums, are free, many of these arts institutions, including the British Museum, the National Gallery and the National Portrait Gallery, actually impose hefty fees for special one-off exhibitions.

As a result, the discerning art lover often ends up paying more in London than in New York, Paris and Rome, said The Sunday Telegraph.

These charges are far greater than those in Paris, where the Louvre and the Pompidou Centre allow anyone aged under 18 free access to permanent collections and special exhibitions.

And the Pompidou's flat entry fee of 12 euros (S$25.70) includes access to the centre's permanent collection and special exhibitions.

British art critic Brian Sewell was quoted as saying by the paper: 'The price of exhibitions in London is, on average, twice as much as what you would pay in any continental gallery.

'I have been to exhibitions in France and Germany recently, which cost just six or seven euros. Our galleries and museums have an annoying habit of branding every show a blockbuster.'

Some of London's most celebrated cathedrals and abbeys are also among the city's most expensive attractions.

Tourists who want to visit Westminster Abbey must pay £12 for a ticket. In contrast, entry to the Notre Dame and Sacre Coeur in Paris is free.

Critics have branded the admission charges in London 'outrageous' and urged tourists to concentrate instead on places they could visit for free.

Mr Gordon Thomson, the editor of listings magazine Time Out, said: 'These charges are outrageous and ludicrous. There is more to the city than these mega tourist attractions.'

Dr Tristram Hunt, a historian, told The Sunday Telegraph: 'The visitor experience at the Tower of London and London Zoo is pretty poor. Other cities are much better at making sure other people have open access. It instils a sense of ownership and pride. But I am afraid it is something that we are very bad at.'