Watch CCTV of the thieves breaking into the Wellbeck Estate.
CCTV has been released of the moment thieves stole a priceless tiara from a display case at the Welbeck Estate in Nottinghamshire.
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.
The centre piece of the item is the Portland Diamond - dating from the 19th century, and flanked by smaller diamonds encased in gold and silver.
The robbers burst into the estate to seize the tiara between 9.45pm and 10pm on Tuesday November 20, 2021, according to Nottinghamshire Police.
The gang cut into cabinets to steal valuable items
CCTV shows the would-be robbers breaking into the Estate using heavy equipment at night. They can be seen using chainsaws to take the wall down.
They can then be seen using the same equipment to remove a valuable object from a case, whilst wearing what look like goggles and overalls.
In a final clip, the burglars can be seen leaving out of the hole they made in the side of the building before climbing back over a border fence and leaving in a car.
Robbers left the Estate out of the hole they made in the wall - before leaving in a car
Police said that within hours of the robberies, the stolen items- along with those from other raids - were sold to jewellers in London.
Cumberpatch and MacDonald were 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 gang later committed burglaries at various addresses - including at the home of the footballer Ashley Cole.