The notoriously exclusive Bilderberg Conference has long been the subject of conspiracy theories, and now Ryanair's Michael O'Leary is set to join the shadowy club.

The airline tycoon's name appears on the list of attendees for this year's discussions in the spectacular Interlaken Hotel in Austria.

The annual conference - which hosts 140 political leaders, academics and captains of industry - takes place between June 11-14.

First held in the Bilderberg Hotel in Oosterbeek, Netherlands in 1957, it was designed to promote Atlanticism - a movement towards closer social and economical links between the US and Western Europe - an aim close to O'Leary and Ryanair.

Along with similar events like Bohemian Grove and the Trilateral Commission, accusations leveled at attendees range from child sacrifice to lizard overlords to the rigging of global finance.

While there remains no convincing evidence for these, the conference agenda says issues like terrorism, cybersecurity, Greece, the Middle-East and many more will be the focus.

Irishman Peter Sutherland, chairman of Goldman Sachs International, will also be making an appearance.