The images were part of the “Bored Ape Yacht Club” collection of NFTs, a set of 10,000 computer-generated cartoon apes, made by United States company Yuga Labs. Owners of the ape NFTs become members of an online club.

An NFT is a digital asset that uses blockchain technology to record who owns a digital object such as an image, video or in-game item. While anyone can view the asset in question, only the buyer can say they are the “official” owner.

Unusually for NFTs, the buyers of Bored Apes also receive the intellectual property rights for the images. They are often used as profile pictures on social media.

The lot contained 101 of these anthropomorphic apes, with different combinations of features such as clothing, accessories and facial expressions, plus the option to generate six new “mutant” ones.

The sale also included a lot of 101 “Bored Ape Kennel Club” NFTs – a set of dogs, marketed as pets for the apes. This fetched US$1.84 million, bringing the total for the sale to US$26.2 million.

Sotheby’s allowed payments in the cryptocurrencies bitcoin, ether and USDC, and fiat currency.