The largest blue star sapphire in the world, weighing 1,404 carats and worth up to £120million, has been discovered in Sri Lanka.

The stone was found in August near Ratnapura, a city in the South of Sri Lanka nicknamed the City of Gems due to its prominent gem trade, local media reported.

It is worth at least an estimated £68million ($100million) but could sell for up to £120million ($165million).

The sapphire's new owner, who wished to remain anonymous, told Sri Lankan newspaper Ceylon Today he felt nervous when he found out it was the largest in the world.

He would not say how much he paid for it.

The 1,404-carat blue star sapphire, which was mined near Ratnapura in the South of Sri Lanka, is the largest of its kind in the world. Its new owner has nicknamed it the Star of Adam, inspired by a Muslim belief that says Adam came to Sri Lanka when he was banned from the Garden of Eden

The stone is too large to be set in jewellery, he added, and should instead be displayed in a museum.

He nicknamed it the Star of Adam, inspired by a Muslim belief that said Adam went to Sri Lanka after God banned him from the Garden of Eden.

According to the myth, he then settled on a mountain now known as Adam's Peak, about 15 miles from Ratnapura.

The Star of Adam, which has been certified by the Gemology Institute of Columbo, has outdone the previous record holder, a 1395-carat blue star sapphire.

Blue star sapphires sometimes have a star in the middle due to a light reflection phenomenon called asterism.

In 2011, Sri Lanka's Gem and Jewellery Association told the BBC that the sapphire on Kate Middleton's engagement ring came from one of the country's mines.

The Duchess of Cambridge's stone, which originally belonged to Princess Diana, is named the Ceylon Blue Sapphire, they said in April.

Seven months later, the National Gem and Jewellery Authority said gem exports had increased by 37 percent throughout the year thanks to increased demand for blue sapphires, notably from the Middle East, Bloomberg reported.