Britain's Prince William has taken a thinly veiled swipe at the billionaires embroiled in a space tourism race, saying the world's greatest brains should instead be focused on solving the environmental problems facing the Earth.

During a BBC interview aired on Thursday, William appeared to criticise Jeff Bezos, the world's richest person, Elon Musk and Briton Richard Branson, whose rival ventures are all vying to usher in a new era of private commercial space travel.

"We need some of the world's greatest brains and minds fixed on trying to repair this planet, not trying to find the next place to go and live," William said of the space race.

His comments come after Musk has spoken about missions to Mars, and Bezos described his inaugural space flight in July as part of building a road to space "so that our kids and their kids can build a future".

Source: Reuters