Twitter chief executive Jack Dorsey has sold his first-ever tweet for more than $2.9million donating the money to a charity battling Covid-19 in Africa.

The tweet has been sold as a unique digital token, known as an NFT (non-fungible token), following a bidding war between Sina Estavi, CEO of cryptocurrency company Bridge Oracle, and tech entrepreneur Justin Sun.

An NFT is a limited edition asset in the digital world, including jpegs and video clips, that can be bought and sold like any other item – but has no physical form of its own.

The NFT works as a certification for ownership of a physical asset which means the NFT will effectively function like a rare trading card.

NFTs are bought using cryptocurrency and run on a blockchain, a decentralised digital ledger that documents transactions, and ownership.

The tweet, which reads “just setting up my twttr” was posted at 8.50pm on March 21, 2006.

After the bid was secured, Mr Estavi wrote on Twitter: “This is not just a tweet!

“I think years later people will realize the true value of this tweet, like the Mona Lisa painting.”

He added that he was “glad this money is being donated to charity”.

The money has been sent to GiveDirectly’s Africa Response, which provides Covid relief.

The tweet will remain publicly available, even now the auction has finished, and indeed could still be deleted by Mr Dorsey.

However, Mr Estavi will receive a digitally signed certificate, verified by Mr Dorsey, as well as the metadata of the original tweet.

Mr Estavi also bid $1.1million to own the NFT of a recent tweet by Elon Musk, in which he wrote: “I’m selling this song about NFTs as an NFT.”

He also owns three other NFTs, valued at less than €130, and has sold NFTs for some of his own tweets for approximately €100.

NFTs have grown in popularity in recent weeks, with artist Krista Kim recently selling a digital house for approximately €500,000.