Original copy of US constitution sold to unknown buyer for $43m

Buyer beats crowdfunded cryptocurrency group to secure one of 13 surviving prints from 1787

A rare surviving copy of the US constitution has sold at auction for a record $43.2m, with an unknown buyer beating a crowdfunded bid by a cryptocurrency group.

The document, one of 13 original copies dating from 1787, sold for almost three times its lower estimate of $15m, and more than 260 times the amount it achieved when it last sold for $165,000 in 1988. The bidding at Sotheby's in New York took eight minutes.