A former Canadian defense minister is demanding governments worldwide disclose and use secret alien technologies obtained in alleged UFO crashes to stem climate change, a local paper said Wednesday.

"I would like to see what (alien) technology there might be that could eliminate the burning of fossil fuels within a generation ... that could be a way to save our planet," Paul Hellyer, 83, told the Ottawa Citizen.

Alien spacecrafts would have traveled vast distances to reach Earth, and so must be equipped with advanced propulsion systems or used exceptional fuels, he told the newspaper.

Such alien technologies could offer humanity alternatives to fossil fuels, he said, pointing to the enigmatic 1947 incident in Roswell, New Mexico -- which has become a shrine for UFO believers -- as an example of alien contact.

"We need to persuade governments to come clean on what they know. Some of us suspect they know quite a lot, and it might be enough to save our planet if applied quickly enough," he said.

Hellyer became defense minister in former prime minister Lester Pearson's cabinet in 1963, and oversaw the controversial integration and unification of Canada's army, air force and navy into the Canadian Forces.

He shocked Canadians in September 2005 by announcing he once saw a UFO.