How much influence do private networks of the rich and powerful have on government policies and international relations? One group, the Bilderberg, has often attracted speculation that it forms a shadowy global government. As part of the BBC's Who Runs Your World? series, Bill Hayton tries to find out more.
The chairman of the secretive - he prefers the word private - Bilderberg Group is 73-year-old Viscount Etienne Davignon, corporate director and former European Commissioner.
In his office, on a private floor above the Brussels office of the Suez conglomerate lined with political cartoons of himself, he told me what he thought of allegations that Bilderberg is a global conspiracy secretly ruling the world.
"It is unavoidable and it doesn't matter," he says. "There will always be people who believe in conspiracies but things happen in a much more incoherent fashion."