Despite Beijing organisers BOCOG stating that all the tickets for events in the host city had sold out in July, swathes of empty seats were often visible at stadiums across the city.

'We are trying to analyse why there were empty seats, it's hard to find out the exact reason,' Mr Gilbert Felli told reporters at the end of the IOC's week-long Beijing debriefing in London.

'People say that it is because we give many tickets to our partners (sponsors) but this is not fair because I think you will find they were sitting in their seats.

'It's a difficult question. Sometimes people do not want to sit for long sessions. Also, discussions we had with our partners at BOCOG suggest that tickets were allocated to different groups around China but sometimes they did not come.'

Beijing organisers even resorted to using hundreds of yellow-clad volunteers to fill empty seats at the tennis, gymnastics and beach volleyball venues.

The issue of ticketing has come into focus after it was discovered that the families of British competitors could get no access to tickets with some losing money to ticket touts, as in the case of swimming gold medallist Rebecca Adlington.

British Olympic Association (BOA) chairman Colin Moynihan said he was in discussions with the London organising committee (LOCOG) to make sure the immediate families of athletes had tickets.

LOCOG chief executive Paul Deighton said every athlete would have access to tickets for family members at the 2012 Games.

'There will be an allocation that will take care of that,' he said.

LOCOG chairman Sebastian Coe said the debriefing had provided valuable lessons for London as preparations for hosting the Games continue.

He said despite the global economic crisis, London was confident it could meet the promises it made to the IOC during the bidding process.

'We are absolutely committed to the promises we made,' Lord Coe told reporters. 'I can't think of any project that is more important to London at the moment than the Olympic Games.' -- REUTERS