A mystery bidder paid $28 million for a seat on a spaceship with billionaire Jeff Bezos during a live auction on Saturday.

It concluded a month-long bidding process for the sightseeing trip on Blue Origin’s maiden voyage next month.

Within four minutes of the opening of Saturday’s live phone auction bids reached beyond $20 million.

The bidding closed seven minutes after the auction began and the identity of the winner was not immediately disclosed.

On July 20 Blue Origin’s New Shepard booster is scheduled to take off from West Texas.

It would be a landmark moment as US firms strive toward a new era of private commercial space travel.

Mr Bezos, founder of Blue Origin and Amazon, is the world’s wealthiest man and a lifelong space enthusiast.

In a video before the final bidding took place he said: "To see the Earth from space changes you. It changes your relationship with this planet, with humanity."

Mr Bezos will also be joined on the trip by his brother Mark.

Thousands of bidders from at least 143 countries entered the auction, Blue Origin said.

The funds raised from the auction will go to charity.

Blue Origin is also hoping to galvanise enthusiasm for its nascent suborbital tourism business.

Richard Branson, who founded Virgin Galactic, reportedly may attempt to steal Mr Bezos’ thunder by joining a possible test flight to the edge of space over the July 4 weekend aboard Virgin’s VSS Unity spaceplane.