American tech billionaire Elon Musk made a surprise address at the campaign launch for Germany’s Alternative for Germany (AfD) party as thousands of people gathered across the country to protest the rise of the far-right party.

"Children should not be guilty of the sins of their parents, let alone their great grandparents," Musk said, apparently referring to Germany's Nazi past.

Musk's support for AfD has helped what was once a fringe political party enter the mainstream, lifting it up in front of a global audience.