Trio convicted of role in theft of £3.5m 'national treasure' Cartier diamond Portland Tiara and brooch

Three gang members have been convicted of conspiracy to commit burglary after a £3.5m tiara worn to the coronation of Edward VII was stolen.

Ashley Cumberpatch, Kurtis Dilks and Andrew MacDonald were all unanimously found guilty of their part in the theft of the Portland Tiara, which has never been recovered.

Nottingham Crown Court heard the 2018 theft of the “national treasure” and its associated brooch, from the Harley Gallery on the Welbeck Estate in Worksop, was a “shocking event” and they will never again be seen in their original state.

The 6th Duke of Portland commissioned Cartier to create the tiara for his wife Winifred, Duchess of Portland.

She wore the diamond-encrusted headpiece, whose centrepiece is the Portland Diamond, to the coronation of King Edward VII, the Queen’s great-grandfather, in 1902.

Cumberpatch and MacDonald were also convicted alongside jewellers Tevfik Guccuk and Sercan Evsin, and co-defendant Christopher Yorke, of converting criminal property following the theft.

Prosecutor Michael Brady QC told jurors the items stolen during the burglary were passed to professional handlers Guccuk and Evsin, who were tasked with selling them.

The court heard it is thought the tiara and brooch were taken out of the country by Guccuk to his native Turkey after they were dropped off at an “ostensibly legitimate jewellery business”, Paris Jewels, in Hatton Garden, London, in November 2018.

Guccuk, who had papers to confirm he was a trader, told jurors his trip to Istanbul was for a rescheduled wedding and that he travels to the city regularly for business.

It is understood his flight was from London Heathrow Airport, and that the 41-year-old would have taken the items in his hand luggage.

Speaking of how the items would have been disposed of in his opening to the jury, Mr Brady said: “Those responsible for this part of what was highly sophisticated criminal offending, Evsin and Guccuk, operated an ostensibly legitimate jewellery business in Hatton Garden.

“Such was the value and conspicuous nature of some of the items stolen that it was not possible to sell them in the UK.

“The inference to be drawn from the evidence is that at times the property had to be disposed of abroad.”

Police rumbled the gang after detectives connected Go-Pro footage of the Harley Gallery, seized from Cumberpatch’s home in October 2017, with the theft.

During the ten-week trial, the prosecution was able to prove the footage demonstrated a reconnaissance attempt by the 37-year-old “in plain sight”.

At the time the footage was seized, detectives were investigating Cumberpatch for possession of a firearm with intent to cause fear of violence – namely a sawn-off shotgun found in a 95-year-old woman’s garden.

He was jailed for seven years for the offence in September 2019.

Addressing the theft of the tiara in his opening, Mr Brady said: “It is difficult to overstate the importance and cultural value of these pieces of jewellery.

“Other works of art that formed part of the same collection included masterpieces by Michelangelo, van Dyck, Stubbs and a pearl earring worn by Charles I at his execution.

“These were trophy pieces of the gallery’s exhibition – extremely valuable, unique and of significant historical importance.

“They were displayed for the public’s enjoyment. Their theft is a shocking event and means that they will never again be seen in their original state.”

All six defendants convicted in connection with the theft of the tiara will be sentenced on July 15.