Not even IOC President Jacques Rogge knows who will light the cauldron at the opening ceremony of the London Olympics.

Rogge says "I'd love to know" but "this is one of the best kept secrets."

Speaking just hours before the ceremony at the Olympic Stadium, Rogge complimented local organizers for managing to keep the identity of the final torchbearer under wraps even from the British media.

Rogge said: "Hats off to the organisng committee."

The IOC leader says it "would be nice" if the cauldron is lit by an Olympic champion.

Five-time rowing gold medalist Steve Redgrave has long been the favorite for the role. Roger Bannister -- the first man to run the mile in under 4 minutes -- is now considered a strong candidate even though he never won an Olympic medal.