A man shattered a sculpture by Chinese artist and activist Ai Weiwei on Friday during the opening of his exhibition at Palazzo Fava in the Italian city of Bologna, a spokesperson for the show said.
Footage from CCTV cameras - posted on Ai Weiwei's Instagram account - showed a man vigorously pushing the sculpture over, breaking it and then holding a piece of it over his head.
The sculpture targeted was the artist's large blue and white 'Porcelain Cube', the spokesperson said.
The exhibit's curator, Arturo Galansino, said the perpetrator was well-known in the art world.
"Unfortunately, I know the author of this inconsiderate gesture from a series of disturbing and damaging episodes over the years involving various exhibitions and institutions in Florence," said Galansino.
The police in Bologna told local media a 57-year old Czech man had been arrested after being stopped by the museum's security. The police could not immediately be reached for comment.
The spokesperson said the art show, entitled "Who am I?" had opened on Saturday as normal and that the oeuvre will be replaced by a life-size print of the cube. The exhibition is due to run until May 4.
"Ai Weiwei worried that no one was hurt and then asked that the remains of the work be covered and taken away," he said.
It was not clear how the man had entered the building during the invite-only event on Friday.