John Cleese has described the digital investment craze surrounding NFTs as “completely absurd” after offering a drawing of his own for sale at £50 million.

The latest tech boom involves “non-fungible tokens”, which have been hailed as a way to sell digital artwork and assets.

NFTs employ technology similar to blockchains such as bitcoin but are unique, one-off assets that are easy to sell or trade but cannot be copied.

Earlier this month, digital artist Beeple sold a JPG file at auction for 69.3 million dollars (£50.6 million) while Twitter founder Jack Dorsey sold his first-ever tweet for 2.9 million dollars (£2.1 million).

Monty Python star Cleese, 81, is getting in on the craze with a tongue-in-cheek offering – an NFT of his drawing of Brooklyn Bridge, sketched on an iPad.

It evokes American con man George C Parker, who was known for attempting to “sell” the New York landmark.

Inspired by Beeple, Cleese offered a buy it now price of 69.3 million dollars and as of Wednesday, the bidding stood at almost 36,000 dollars (£26,300).

Cleese told the PA news agency the art world has “mystified him” for years.

“It is a completely absurd situation,” he said of NFTs. “There’re so many absurdities in life these days you’d hardly notice another one.

“This one got noticed of course because 69 million is such a huge amount of money but I’ve always had a certain scepticism about modern art, that it is not really concerned with creating beauty.”

Citing the example of Tracey Emin’s 1998 work My Bed, Cleese added: “I mean, when you have an unmade bed and everyone says, ‘What a wonderful piece of art’. Well, you didn’t have to go to an art gallery to look at an unmade bed.

“And if you want to have thoughts about an unmade bed you could do it at home. So I’ve been mystified for years – even though I’m partly creative myself – for what passes for art.

“And this is just another extreme example of it.”

Cleese, who said he would welcome his NFT fetching a high price, suggested the modern art world is going through a barren spell.

The popularity of digital products may be an indication of a wider malaise, he said.

I think the problem is this; there are some periods when art, movies, theatre, whatever, are particularly good and then there are other periods when they're not. And it's not really in anyone's interest to point out when they're not

Cleese told PA: “I think the problem is this; there are some periods when art, movies, theatre, whatever, are particularly good and then there are other periods when they’re not. And it’s not really in anyone’s interest to point out when they’re not.

“I mean, art dealers are not going to go around saying, ‘Well, there’s nothing really much good at the moment’. It wouldn’t be in their own interests. It would be a bit like a newsreader saying, ‘Good evening, I’m afraid there isn’t any news today’.

“You have to pretend it’s exciting and new, otherwise you can’t get people to depart with their money. But I think an enormous proportion of it is bullshit.”

The auction for Cleese’s Brooklyn Bridge NFT is due to end on April 2. As of Tuesday, the top bid was from a user named “JeffBezosForeskin”.

Cleese has not ruled out creating more NFTs.

“I do have some ideas for pictures,” he said. “I would like to make people smile. It’s not much of an emotional reaction but it’s better than staring at an unmade bed and thinking, ‘Oh, that’s interesting’. It’s nice to make people laugh.

“If you tell a story and everyone laughs, you feel good, they feel good. I like making people laugh, it’s as simple as that.”