The final four members of an organised crime group trading in rhino horn have been found guilty of conspiracy to burgle after a two-month trial at Birmingham Crown Court.

The verdict was delivered on Monday (29 February) as part of three linked trials involving a total of fourteen gang members responsible for raids on UK museums and an auction house between November 2011 and April 2012. Up to £57 million worth of artefacts were stolen during the thefts, a figure which dwarfs that of the Hatton Garden bank vault heist in which £14 million worth of items were stolen.

Described as the gang’s “generals”, the four men convicted on Monday are thought to have been responsible for planning and overseeing the burglaries. The remaining gang members were convicted earlier hearings. Hailing from Cambridgeshire, Essex, Kent, London, the West Midlands and Northern Ireland, the gang members are known as the ‘Rathkeale Rovers’ or alternatively the ‘Dead Zoo Gang.’

The raids targeted Chinese artefacts from the Qing and Ming dynasties especially jade and rhino horn. Rhino horn is highly sought after on the Chinese market for use as a medicine and a party drug and a single horn can command up to £220,000.

Among the most profitable raids was that on Durham University’s Oriental Museum on 5 April 2012. Entering the Museum via a hole chiseled in a 2ft by 3ft wall the gang stole a Ming dynasty jade bowl and a porcelain figurine valued at up to £2 million. A few short days later the gang raided Cambridge’s Fitzwilliam Museum smashing glass display cases and stealing £15 million worth of mainly jade artefacts.

Despite the huge value of their haul, the gang members were not the slickest band of thieves. Prosecutor Robert Davies told the courtroom in Birmingham that shortly after making off with the priceless Ming bowl the gang members lost it on wasteland near an industrial estate in Durham:

“It all came to nothing when they had not, pirate-style, put a cross on a map,” Davies said.

Following coordinated raids by police officers and a four-year covert national investigation the gang members were finally apprehended. They are due to be sentenced on 4 and 5 April 2016 at Birmingham Crown Court.