Joseph Lau  Blue Moon diamond
Hong Kong property tycoon Joseph Lau bought the Blue Moon diamond for $48.5m for his young daughterReuters

The most-expensive diamond ever auctioned has been bought by a fugitive Hong Kong billionaire for his daughter, his office confirmed. Joseph Lau, a property tycoon paid 48.6m Swiss francs ($48.5m, £31.7m) for the exceptionally large blue 12.03-carat diamond at a Sotheby's jewellery auction in Geneva.

Lau, who is wanted in Macau to serve a jail sentence on corruption charges, renamed the rare coloured stone The Blue Moon of Josephine after his seven-year-old daughter. A day earlier, the 64-year-old gave a similar name Sweet Josephine to a pink diamond ring he separately purchased at Christie's for $28.5m.

The auction houses didn't identify the buyer but Lau's office confirmed he had acquired them. "Yes, the two diamonds are bought by Joseph Lau," a spokeswoman told AP. The property developer reportedly owns another "Josephine" stone, a 7.03 carat blue diamond auctioned at Sotheby's in 2009 for $9.5 million and renamed by the buyer the Star of Josephine.

The property developer, who Forbes ranked the 114th richest man in the world, estimating his fortune at $9.8 billion, was handed a five-year term by a Macau court last year in a high-profile bribery and money-laundering case.

He has denied any wrongdoing, but didn't attend the trial. He has nevertheless avoided prison, as Macau and nearby Hong Kong, two specially administered Chinese regions, do not share an extradition treaty.

The Blue Moon sale set the new world auction record for any jewel, topping the $46.2m paid in 2012 for a 24.78-carat diamond known as The Graff Pink.

"Tonight we set a new world record, a new auction record for any diamond, any jewel, any gemstone, with the sale of the Blue Moon diamond," said auctioneer David Bennett. "For me, the Blue Moon was always the blue diamond of my career. I have never seen a more beautiful stone. The shape, the colour, the purity — it's a magical stone."

Lau had Josephine, his youngest daughter, with his current partner Chan Hoi-wan, a former entertainment reporter, according to the South China Morning Post. The divorcee has also fathered another four children with two other women, his former partner, Yvonne Lui, and ex-wife Bo Wing-kam.

Blue Moon Diamond
The rare Blue Moon diamond has been sold for a record $48.26m (£31.7m) in GenevaAFP/Getty Images