The Nobel Prize gold medal awarded to the US scientist and co-discoverer of DNA, James Watson, sold at auction for more than $4.7 million, smashing the world record price for any Nobel prize.

The medal, which Christie’s auction house had estimated would sell for anywhere from $2.5 million to as much as $3.5 million, was the first Nobel put on sale by a living recipient.

Christie’s did not disclose the buyer, who was bidding via telephone and paid $4,757,000, including commission.

The price and record “demonstrate the growing strength in the market for the iconic pieces related to the early understanding and development of the implications of DNA and its growing relevance today,” said Francis Wahlgren, international director of books and manuscripts at Christie’s.

Watson, along with Francis Crick and Maurice Wilkins, unravelled the double-helix structure and function of deoxyribonucleic acid (DNA) in Britain in 1953 in a discovery that heralded the modern era of biology.

The scientists received the Nobel Prize for medicine in 1962 for their groundbreaking work in genetics. Watson, 86, said he planned to donate part of the proceeds to charities and to support scientific research.