Two men have been jailed for their roles in the “bold and brazen” theft of a £4.75m gold toilet from an art exhibition at Blenheim Palace.

James Sheen, 40, and Michael Jones, 39, were sentenced at Oxford crown court for their roles as part of a gang who planned and carried out the burglary at the Oxfordshire stately home, receiving a four-year prison sentence and a 27-month prison sentence respectively.

The 18-carat fully functioning lavatory, which weighed around 98kg, was stolen in September 2019 while it featured in an art exhibition in just five minutes by sledgehammer-wielding thieves who smashed their way in, the court heard.

The thieves drove through locked wooden gates into the grounds of the palace in two stolen vehicles before breaking in through a window. It is believed the toilet was broken up and disposed of. None of the gold has been recovered.

Sheen, of Wellingborough, Northamptonshire, had previously admitted burglary, conspiracy to transfer criminal property and one count of transferring criminal property. Jones, of Oxford, was found guilty of burglary after a trial.

The artwork, which had previously been on display in New York City, was created by the Italian artist Maurizio Cattelan, and was plumbed in at the time of the heist, so its removal led to flooding and resulted in damage to the 18th-century stately home and Unesco world heritage site where Winston Churchill was born.

Cattelan created the sculpture – called America – to reflect the excesses of the art market and evoke the American dream of opportunity for all. It was made from gold that was itself worth about £2.8m.

Passing sentence, Judge Ian Pringle KC said: “This bold and brazen heist took no more than five-and-a-half minutes to complete. America has never been seen again.”

Sheen was jailed for four years and his sentence will run consecutively to the 19 years and four-month sentence he is serving for attacks on cash machines, a museum burglary and fraud.

“You were part of the gang of five men who smashed their way into Blenheim Palace that night and stole the hugely valuable golden toilet,” the judge said.

“You were almost certainly the figure that carried the sledgehammer on which your DNA was found and which was used to sever the functioning toilet from its connecting pipes.

“I say straight away I have no doubt at all that the sentence I pass must be consecutive to the sentence you are currently serving. Not to do so would be to send out a message that you did this without any penalty at all.”

Pringle jailed Jones for 27 months after concluding he could not be sure he was part of the gang that had carried out the burglary. “You paid visits on two occasions to Blenheim Palace in the days leading up to the burglary,” he said.

“That your role was to carry out a reconnaissance of the museum, to know exactly where the golden toilet was situated and to work out the quickest route in and out of the palace, I have absolutely no doubt whatsoever.

“Although you have no witnesses to where you were on the night in question, I cannot be sure that you were part of the group of burglars who broke into the palace that night.”

Gold from the toilet may have been smuggled out of the UK as police hunt a “significant amount” in criminal assets linked to the thieves behind the heist.

Sheen is believed to have had the toilet broken up before he tried selling the parts to underworld contacts, prompting searches in Birmingham and Hatton Garden in London, Thames Valley police said.

But the force said it was working with international partners and had not ruled out the chance that the gold was moved overseas. Det Supt Bruce Riddell told PA media: “It could have got abroad.”

He said the next stage of the investigation was the identification and recovery of criminal assets, including luxury goods bought after the crime.

Riddell said the investigation after the toilet theft was “complex”, with hundreds of hours of CCTV footage reviewed, more than 2,000 statements recovered, mobile devices seized and 12 people arrested in total.