Tennis ball-sized diamond could fetch more than £50 million at Sotheby's auction

A tennis ball-sized diamond could fetch more than £50 million when it goes under the hammer at auction.

The 1,109-carat Lesedi la Rona was unearthed in Botswana last November and is set to go on sale in London in June.

The diamond is believed to be the second largest gem-quality rough diamond ever to be discovered and the biggest of its kind to be found in over 100 years.

Experts predict the Lesedi la Rona could surpass its £48 million guide price.

The record paid for a diamond is currently £33.4 million

David Bennett, worldwide chairman of Sotheby’s jewellery division, said: “The Lesedi la Rona is simply outstanding and its discovery is the find of a lifetime.

“Every aspect of this auction is unprecedented.

“Not only is the rough superlative in size and quality, but no rough even remotely of this scale has ever been offered before at public auction.”

The auction at Sotheby’s takes place on June 29.