Six Cambridgeshire men guilty of masterminding series of museum raids, including Cambridge's Fitzwilliam

Between November 2011 and April 2012, Chinese artefacts and rhinoceros horns worth millions of pounds were targeted in six incidents – two thefts and an attempted theft from Durham University Oriental Museum, robberies at Norwich Castle Museum in Norfolk and Gorringes Auction House in East Sussex and a burglary at the Fitzwilliam Museum in Cambridge.

Investigations were launched by local police forces and a number of people convicted for their parts in carrying out the thefts.

However, it soon became apparent that an organised crime group was planning and commissioning the jobs.

‘Operation Griffin’, an investigation led jointly by Cambridgeshire and Durham Constabularies, and supported by the National Crime Agency (NCA) and the National Police Chief’s Council (NPCC), was launched in June 2012 to bring those behind the conspiracy to justice.

Daniel ‘Turkey’ O’Brien, 45, John ‘Kerry’ O’Brien, 26, Michael Hegarty, 43, and Richard ‘Kerry’ O’Brien Junior, 31, all from Cambridgeshire but with links to Rathkeale in Ireland, were yesterday (Monday, February 29) found guilty of conspiracy to steal today, following an eight-week trial at Birmingham Crown Court.

Eight other men, aged between 33 and 68, from Cambridgeshire, London, Southend-on-Sea and Wolverhampton, were found guilty at three previous trials, all at Birmingham Crown Court. Two others, one aged 28 from Kent, and the other aged 46 from Belfast, pleaded guilty to the charges in March last year and January this year.

Reporting restrictions were put in place by the judge until all the defendants had faced trial, that process is now complete.

All 14 men were charged in connection with all six incidents.

Senior Investigating Officer for the operation, Detective Superintendent Adrian Green from Durham Constabulary, said: “I am extremely pleased with the verdicts passed today and over the previous year.

“Because of the variations which can be given by auction houses the total value of the items targeted comes to anywhere between £18m and £57m. This illustrates just how massively profitable this trade was viewed by the gang.

“All the hard work put in by everyone involved has paid off; firstly, those that carried out the burglaries were caught and convicted by local officers. What followed was a very long and complex investigation to capture and bring to justice those who commissioned and planned the jobs.

“I hope this sends out a message that nobody is untouchable.”

Derbyshire Chief Constable Mick Creedon, the national policing lead for organised crime said: “This complex and lengthy operation resulted from initial work done by the Cambridgeshire and Durham forces who uncovered the offending of a sophisticated criminal network responsible for a series of high value offences across the country.

“These convictions are the result of a nationally co-ordinated investigation involving the National Police Chiefs Council, numerous police forces, the National Crime Agency, HM Revenue and Customs and significant international liaison in Europe and beyond, all coupled with close working with the Crown Prosecution Service and prosecuting counsel.

“Organised crime takes many forms and seeks to exploit any opportunity to harm communities and make criminal profit. This case starkly demonstrates the level of threat, the lengths criminal gangs will go to and the importance of law enforcement agencies sharing intelligence and working together, nationally and internationally.”

A date for sentencing is yet to be confirmed.