The national tourism agency revealed research it has commissioned suggested that the 2012 Olympics has the potential to generate £2 billion for the tourism economy.

It contradicts another report published this week by the European Tour Operators Association (ETOA) which claimed that “post-Olympic blight” had affected every host nation since the Seoul Games of 1988

In a statement, VisitBritain indicated that the economic benefits will not been seen directly during the Games but in the "window of opportunity that will be created before and after".

The agency believes that "two thirds of the revenue is forecast to be generated in the post-Games years (from) 2013 to 2017".

However, in order to realise the benefits of the event for tourism, a properly researched and financially backed strategy must be implemented.

VisitBritain, Visit London, and the Department of Culture Media and Sport are working with industry to generate this "clear and comprehensive strategy".

The agency said that the world's biggest sporting event offers Britain the chance to "make a step change to our tourism industry and its image overseas".

"Britain's image can be re-invigorated and the country's appeal broadened to younger travellers and viewers in new markets who do not have strong ties to Britain."

"To remain internationally competitive it is important that we attract visitors from these fast-growing markets. The opportunities that the Games present are immense," he added.

VisitBritain believes in excess of 10,000 unaccredited media representatives will travel to London for the Games and can help create a lasting "buzz" around London.