The number of people travelling to London on sight-seeing holidays could drop dramatically during the 2012 Olympics, the tourism industry is warning.

A survey by the European Tour Operators Association, responsible for two million tourists each year, suggests tour operators to the UK have seen an average 90% downturn in bookings for the period of the London Olympics.

The association says the data is "in stark relief" to expectations raised by the hotel industry and the London Organising Committee of the Olympic and Paralympic Games (LOCOG).

Joe Lynam reports.