An 2.5m-deep installation by the British sculptor Sir Anish Kapoor has left an Italian man in his 60s hospitalised.
Descent into Limbo (1992) is a dark hole like an abyss installed in the centre of the floor inside a large concrete cube with a single door.
The sides of the hole are coated in black pigment, giving the illusion of a depthless void.
The museum said all security measures had been followed, including warning signs and a member of gallery staff positioned inside the installation.
It has been temporarily closed while the institution assesses what happened but it hopes to reopen it in a few days.
Prize-winning artist Kapoor often plays with optical illusions that create the impression of infinite depths in his work.
In 2016 he acquired exclusive rights to Vantablack, a pigment developed by British company NanoSystems that absorbs 99.96% of light.
Descent Into Limbo debuted years before Vantablack was announced to the public, and was instead created using a dark paint that produces the same black hole effect