It is believed that the distinctive fully functioning toilet, entitled America, which had been installed as an artwork at the Oxfordshire country house where Sir Winston Churchill was born, has now been split up and disposed of, Oxford Crown Court was told on Monday.
The toilet, which was created by Italian artist Maurizio Cattelan, was a star attraction in an exhibition when it was stolen by sledgehammer-wielding thieves who smashed their way into the palace.
Within days of the raid, two men were using "car" as a codeword for the stolen gold and contact was made with a Hatton Garden jeweller, the prosecution said.
Prosecutor Julian Christopher KC said the raid took just five minutes, adding: "This case concerns the theft of a work of art from Blenheim Palace in September 2019.
"It was an unusual work of art, being a fully functioning toilet made of 18 carat gold, entitled America.
"It weighed approximately 98kg and was insured for the sum of six million dollars ($A9.44 million)
"The gold it was made from was itself worth in the region of 2.8 million pounds ($A5.6 million) at the time."
Michael Jones, 39, is standing trial charged with one count of burglary, to which he has pleaded not guilty.
Fred Doe, 36, and Bora Guccuk, 40, are charged with one count of conspiracy to convert or transfer criminal property, namely gold, which they deny.
A fourth man James Sheen, 39, has previously pleaded guilty to burglary.
The trial is due to last four weeks.
The court heard that the sledgehammers were left at the scene.
"The burglary was carefully planned and swiftly carried out," Christopher said.
"The men, five of them it appears, drove through locked wooden gates into the grounds of Blenheim Palace shortly before 5am in two stolen vehicles, an Isuzu truck and a VW Golf.
"They drove across a field, up to the front steps and smashed and broke in through a window.
"They knew precisely where to go, broke down the wooden door to the cubicle where the toilet was fully plumbed in, removed it, leaving water pouring out of the pipes, and drove away.
"All in all they spent just five minutes in the building.
"Clearly such an audacious raid would not have been possible without lots of preparation."
A photograph was taken about 17 hours before the toilet was stolen and the prosecution allege that Jones had taken it while he was "there as part of the reconnaissance for the burglary".
"The work of art was never recovered. It appears to have been split up into smaller amounts of gold and never recovered," the prosecutor said.
Jones was arrested on October 16, 2019, and police analysed his phone. He had allegedly been searching for newspaper reports about the stolen toilet on September 20.
The trial continues.