Inside the main hall of the Accademia gallery in Venice, beneath a carved, gilded ceiling decorated with cherubs’ heads, a mysterious black square is hovering above a white plinth. Carefully protected inside a glass case, it appears as alien as a slab of kryptonite. 

This is "The Telegraph"´s chief art critic speaking - as I certainly did not make it to Venice this week. But having read Alaistar Sook about Anish Kapoor - I certainly will. Love the Bombay born Londoner since the first time I saw his art in 1992.

Sook´s review goes on:

As you walk past the square, something strange and unexpected, even magical, happens: it starts to swell. Standing in front of it, you’d swear that it was flat. Yet, viewed side-on, the square’s seemingly 2D middle plainly bulges outwards, occupying three dimensions. That flatness was an illusion: whatever this spooky shape is, it’s apparently growing before our eyes, like Pinocchio’s nose. 

In fact, it is one of several mesmerising new sculptures that, exhibited in Venice for the first time, have been created by the British-Indian artist Anish Kapoor using a special black pigment produced with carbon nanotechnology by a scientific-research company, and licensed to the artist. (When the deal was announced a few years ago, it ruffled the feathers of a few artists who baulked at the idea of Kapoor ring-fencing a newly invented colour for himself.) 

According to its manufacturer, so-called “Kapoor Black” absorbs around 99 per cent of all light that hits it – making it, apparently, blacker than a black hole.

There are plenty of Kapoor’s paradoxical black sculptures in his new Venetian show of around 70 works, arranged across two venues in the city. The exhibition is a big moment for the 68-year-old artist, not least because the second setting, near the ghetto in Cannaregio, is a dilapidated palazzo, around the corner from the low-slung train station, which Kapoor’s foundation acquired three years ago. Slowly, it is being transformed into a cultural centre, due to open in 2024 – although the renovations still have a way to go. 

But, because they’re new, Kapoor’s cryptic black sculptures are grabbing all the attention. Downstairs in the Accademia’s temporary exhibition spaces (Kapoor is the first Brit invited to show at the gallery), there’s an entire room of them, all seemingly sprouting various shapes, including diamonds and elongated doorknobs, as well as humps. 

Are they gimmicky? Perhaps. A strand of Kapoor’s oeuvre, predicated upon optical illusions, has always had a funfair quality, and these black sculptures, which make me think of 1980s executive toys, certainly belong to it. Yet, they’re also in a perpetual state of “becoming” – which, sculpturally, is a considerable invention: by offering objects that appear to be simultaneously flat and not flat, Kapoor presents a serious conundrum. The chief frustration is that, to preserve the density of the pigment, the works are boxed inside vitrines, and the reflections in the cases’ surfaces prove distracting. 

The exhibition contains much else besides, including lots of gory, mucky, visceral paintings and sculptures, reminiscent of disembowelled innards and spurting blood, which are more repellent than crowd-pleasing. 

In his three-dimensional work, Kapoor remains obsessed with fissures, tears, slits, and cracks: throughout both shows, the (how to put this delicately?) vaginal imagery is unmistakable. 

And, upstairs at the tumbledown Palazzo Manfrin, Kapoor stages an unmissable installation, featuring a vast red disc and industrial conveyor belts carting about his familiar claret-coloured gloop. In one corner, a shabby Madonna tramples upon a Satanic serpent with a prominent red tongue. This detail delights Kapoor, who tells me that she is trying to “subdue” the “shamanistic energies” which “I am trying to get out.” Not half: Kapoor’s powerful new exhibition positively crackles with black magic.

From April 20 until Oct 9; information: gallerieaccademia.it