Members of a skilled organised criminal gang at the heart of a £57m conspiracy to "plunder" British museums of rhino horn and other priceless Chinese artefacts have been jailed for up to six-and-a-half years.
The group, dubbed the 'Rathkeale Rovers' because of their links to the Limerick town, targeted high-value objects in a string of break-ins, including Cambridge's Fitzwilliam Museum and twice at Durham's Oriental Museum in 2012.
Judge Murray Creed heard that although the items stolen in Durham and Cambridge were valued at up to £18 million, detectives believe they might have fetched more than three times that figure on the booming Chinese auction market.
Members of the same gang also masterminded a bungled attempted theft at Gorringes Auction House in Lewes, East Sussex, and organised the disposal of stolen artefacts in what the judge said was "an extremely sophisticated conspiracy".
Sentencing members of the 14-strong gang, Judge Creed said on Monday: "It is a conspiracy both sophisticated, skilled and persistent, and involved significant cultural loss to the UK of museum quality artefacts and items from international collections."
In all, 13 men have been sentenced over two days, after three trials which concluded with the gang and its associates convicted of wide-ranging criminal conspiracy to steal, with connections to Ireland, Europe and China.
John "Kerry" O'Brien, aged 26, of Orchard Drive, Smithy Fen, Cottenham, Cambridgeshire - but also of Rathkeale, Co. Limerick - was said by the judge to have had a central role in the conspiracy. He was jailed for six-and-a-half years.
Terrence McNamara, of Marquis Street in Belfast, was told he would be jailed for four years.
Addressing 43-year-old Michael Hegarty, also of Orchard Drive in Cottenham, and Rathkeale, he said: "I believe you were controlling him (McNamara) in relation to events at Durham Museum in the first instance."
Hegarty was jailed for six-and-a-half years.
He sentenced 47-year-old Richard Sheridan, of Water Lane in Smithy Fen, and Patrick Clarke, aged 34, of Melbourne Road, Newham, London, to five-and-a-half years apiece for their part.
Ashley Dad, aged 35, of Crowther Road in Wolverhampton, who did not appear at court, was jailed for five years and three months.
On Monday the judge sentenced seven other men to between four years and six years and eight months behind bars, including "fence" Donald Wong, while another man had already been jailed for his part.
Sheridan is a former spokesman for the Dale Farm travellers site in Essex and was seen in Wong's company, shortly before £50,000 in cash was found in Chinese businessman's car.
The judge said the operation to "plunder" rhino horn, carved horn and jade items started off "small-scale" in January 2012, but that after initial failures and botched thefts - in one case the burglars forgot where they had hidden their haul - "planning paid off".
"It was serious organised crime," he added.
In their most successful theft 18 pieces of Chinese jade were stolen from the Fitzwilliam Museum and although experts provided various valuations up to almost £18m the judge described them as "priceless".
He added: "They were part of a national collection split between the museum in Cambridge and the British Museum in London."
Afterwards, that haul was stored in a safe house before being taken by taxi to Purfleet in Essex where the goods were spirited away.
The judge continued: "The conspiracy spanned England, Scotland, Northern Ireland and the Irish Republic, references were made to France - the Cherbourg visit, Hong Kong and also the United States and Germany, also featured in the evidence the court heard over the three trials."
He said the gang had either stolen or tried to steal "highly prized museum-quality" items, often with historic Imperial Chinese dynastic connections, with the exception of an attempted theft on an auction house in March 2012 in which the bungling thieves took the wrong item.
On two occasions the Oriental Museum in Durham was targeted, but also the Castle Museum in Norwich, Gorringes Auction House in Lewes, East Sussex, and the Fitzwilliam Museum.
The men carried out reconnaissance of these and other sites, including three museums in Glasgow, and another auction house in Yorkshire.
The judge said the conspiracy had been centred on the family seat in Rathkeale, telling the defendants: "At the heart of this enterprise was a family - a number of you are members of the O'Brien family."
He added: "Of 14 original conspirators, seven were connected with that home, seven were associates, like Terrence McNamara, while others were recruited in to find thieves prepared to carry out burglaries, particularly in carrying out the second attack on Durham museum.
"No doubt others were involved too."
Robert Gilbert Smith, formerly of Hockenden Lane in Kent was jailed for his part in the crime last year.