Britain’s most prolific supergrass is in hiding after giving crucial evidence against members of organised crime groups operating in the North East of England.
More than 20 criminals were jailed for over 250 years following six trials at Teesside Crown Court between 2018 and 2021.
Prosecutors said the evidence provided by the “assisted witness” who will be a target for life, was "on a wholly unprecedented and exceptional scale".
One gang attempted to smuggle cocaine worth around £2 million into the North East from Brazil, via Tilbury Docks in Essex.
The North East leader of the gang, David Gloyne, planned the job with international drugs dealer Yvan Nikolic, a Montenegrin who lived in France.
In August 2015, the two met at a hotel near the docks, along with other members of the group. The group stayed over and the following morning went to Tilbury Docks dressed in yellow high-vis jackets.
In search of a container from Brazil containing a 50 kilo consignment of cocaine, security staff stopped the group because they were wearing the wrong coloured high-vis.
The drugs were later seized by police and the organised crime group left without their haul.
With the group short on cash, tensions rose when David Gloyne discovered a member of the gang had hatched a plan to steal 27 kilos of cocaine from a safe house.
The member of the gang, who became the 'supergrass', is only known as Mr X.
Gloyn's associates tracked Mr X down, kidnapped and tortured him.
Gloyne then found out another member of the gang had helped Mr X.
The man was kidnapped and assaulted, but managed to escape in a car to a police station.
Police searched the car and located two kilos of cocaine in the boot. Further forensic analysis found it was connected to the Tilbury Docks drugs.
Police launched Operation Everest in response to the Tilbury Docks incident and five more spin-off cases were launched on the back of information provided by Mr X.
Yvan Nikolic, the mastermind of the Tilbury dock smuggling incident, was sentenced to 21 years for conspiracy to supply cocaine.
His co-accused David Gloyne, from Plawsworth, County Durham, was the head of an organised crime gang and was also jailed for 21 years at Teesside Crown Court after he was convicted of conspiracy to supply, kidnap and false imprisonment.
The supergrass had to admit to all of his criminal wrongdoings in order to assist the police investigations.
In all he admitted 23 offences, which could have led to him receiving 14 years in prison, but after the “cleansing” period of coming clean over his crimes, he was handed a heavily reduced sentence of 15 months suspended for two years.
He had crucial information about a wide range of offenders and crimes, including a shooting and a serious arson.
Taking the witness box for 41 days during six trials and amid tight security, his identity is now protected by court order.