HAVANA, Cuba — Fidel Castro says al-Qaida leader Osama bin Laden is a bought-and-paid-for CIA agent who always popped up when former President George W Bush needed to scare the world, arguing that documents recently posted on the Internet prove it.

"Any time Bush would stir up fear and make a big speech, bin Laden would appear threatening people with a story about what he was going to do," Castro told state media during a meeting with a Lithuanian-born writer known for advancing conspiracy theories about world domination. "Bush never lacked for bin Laden's support. He was a subordinate."

Castro said documents posted on WikiLeaks.org — a website that recently released thousands of pages of classified documents from the Afghan war — "effectively proved he was a CIA agent." He did not elaborate.

The comments, published in the Communist Party daily Granma today, were the latest in a series of provocative statements by the 84-year-old revolutionary, who has emerged from seclusion to warn that the planet is on the brink of nuclear war.

Castro even predicted the global conflict would mean cancellation of the final rounds of the World Cup last month in South Africa. He later apologised for jumping the gun. Last week, he began highlighting the work of Daniel Estulin, who wrote a trilogy of books highlighting the Bilderberg Club, whose prominent members meet once a year behind closed doors.

The secretive nature of the meetings and prominence of some members — including former United States Secretary of State Henry Kissinger, senior US and European officials, and major international business and media executives — have led some to speculate that it operates as a kind of global government, controlling not only international politics and economics, but even culture.

During the meeting, Estulin told Castro that the real voice of bin Laden was last heard in late 2001, not long after the September 11 attacks. He said the person heard making warnings about terror attacks after that was a "bad actor."

Castro stepped down due to ill health in 2006 — first temporarily, then permanently — and handed power over to his younger brother Raul. He has remained head of the Cuban Communist party but stayed out of view for four years after falling sick before returning to the spotlight in July.

Castro did take exception with one of Estulin's major theses: that the human race must move to another habitable planet or face extinction.

Castro said it would be better to fix things on Earth then abandon the planet altogether.

"Humanity ought to take care of itself if it wants to live thousands more years," Castro told the writer.