The fully-functioning piece by Italian artist Maurizio Cattelan, dubbed “America”, was once displayed at New York's Guggenheim museum and offered on loan to US President Donald Trump.
A 66-year-old man has been arrested over the theft at the 18th-century stately home in Oxfordshire, which caused flooding at the World Heritage Site.
“The offenders broke into the palace overnight and left the scene at about 4.50 am. No-one was injured during the burglary,” local police said.
Detective Inspector Jess Milne said: “The piece of art that has been stolen is a high-value toilet made out of gold that was on display at the palace. Due to the toilet being plumbed into the building, this has caused significant damage and flooding. We believe a group of offenders used at least two vehicles during the offence.
“The artwork has not been recovered at this time but we are conducting a thorough investigation to find it and bring those responsible to justice.”
Cattelan told the New York Times that when he first heard news of the theft, he hoped it was a prank.
“Who's so stupid to steal a toilet? I had forgotten for a second that it was made out of gold,” he said, adding: “I wish it was a prank.”
Maurizio Cattelan's gold toilet, 'America'. Photo: William Edwards/AFP
Cattelan has described the 18-carat gold work as “one-percent art for the 99 percent”.
“I hope it still is. I want to be positive and think the robbery is a kind of Robin Hood-inspired action,” he said, referring to the character of English folklore who stole from the rich to give to the poor.
Blenheim Palace chief executive Dominic Hare meanwhile revealed that the toilet, which was only put on display at the English stately home on Thursday, had been valued at around $5 to $6 million.
He told the BBC that the palace, the birthplace of wartime leader Winston Churchill and a UNESCO World Heritage site, had a sophisticated security system. But he added: “Clearly we need to challenge ourselves on that.”
He also said it was “not out of the question [that it] would be melted down” by the thieves.
Maurizio Cattelan. Photo: Alain Jocard/AFP
The toilet was one of the star attractions in an exhibition of Cattelan's works, with visitors able to book three-minute time slots to use it.
When the work was on display at New York's Guggenheim museum, more than 100,000 people lined up to use the loo during the course of a year.