A diamond-encrusted crocodile-skin Hermes handbag with white gold details has broken the record for the world's most expensive ever sold at auction, fetching nearly US$380,000 at a Hong Kong sale.

The rare Himalaya Niloticus Crocodile Diamond Birkin 30 went to an unknown phone bidder Wednesday for HK$2.94 million after intense bidding, a spokeswoman for auction house Christie's told AFP.

The new record beat one set last year, also in Hong Kong, by an identical Hermes bag that sold for HK$2.32 million.

Only one or two Diamond Himalayas are created each year globally, making it one of the rarest production runs for handbags, according to Christie's.

"It actually has been rumoured that they will discontinue Himalayas altogether this year, which may be part of the reason that we've seen the increase in the value this season," Matthew Rubinger, Christie's international head of handbags and accessories division, told AFP.

Designer handbags are increasingly seen as investment opportunities and have become a craze for collectors, taking global auction houses by storm and scoring record prices. 

The handmade bag -- described by the London-based auctioneers as "the most desirable handbag in existence" -- is encrusted with diamonds, while the buckle and trademark mini Hermes padlock are from 18 carat white gold.

The bag was made in 2014 and is from Hermes' "Birkin" series named after actress and singer Jane Birkin, who was born in Britain and lives in France.