Until his arrest, Roberts was thought to be running his huge drug operation from London in conjunction with Britain's number one crime family, the Turk-Cypriot Arif gang.
A source claimed: "Roberts is a lieutenant in the Arif gang.
Three of the seven Arif brothers are behind bars for long sentences.
In 1999, 45-year-old Bekir Arif was convicted of conspiracy to supply 100kg of heroin worth EUR19million and jailed for 23 years.
Dennis and Mehmet Arif are serving 22 and 18 years respectively for a 1991 armed robbery.
A cop who has spent half a lifetime on the family's case said: "The Arifs are one of the most awesome gangs of villains ever seen in London.
As he lay dying on the floor, the five-man gang - part of the fearsome Arif Family - simply smirked at his desperate cries for help.
Ozer Arif - then a 28-year-old minicab boss from Southwark, south London - was charged with murder.
TOMMY ADAMS FAMILY; TERROR: Ruthless gang open fire on security guards at point-blank range, killing a dad of three; FEARSOME: Bekir Arif; Got 22 years after the same armed raid on Securicor van; DOGAN ARIF; Had run-in with Mafia after 'confiscating' their cocaine; MEHMET ARIF; Jailed for 18 years for his part in pounds 1 million armed robbery; DENNIS ARIF