A MEMBER of one of Scotland's top criminal gangs was caged today after he was found to be involved in a major drug production plant. 

Hugh McHugh, 43, was sentenced to five years and four months for his role in a factory-scale operation in Johnstone producing the so-called "blue plague" of Etizolam, or street Valium. 

READ MORE: David 'Murfy' Hough jailed after raid on valium factory and safe house in Glasgow

He's the fourth member of what police have called "Scotland's top-tier organised crime groups" to be jailed after a major crackdown on organised crime called Operation Gadget. 

Three of McHugh's accomplices, David Hough, James Dalziel and Eric Morrison junior, have already been sentenced to a total of more than eleven years in prison.

Officers uncovered major hauls of heroin, cocaine, Etizolam, and mixing agents. They raided an industrial building in Johnstone, which was being used as an industrial-scale pill production factory.

READ MORE: UK's 'biggest ever' mob crackdown sees David Hough and James Dalziel caged

A number of revolvers, shotguns, ammunition and grenades were also seized by cops.

Detective Superintendent David Scott, of Greater Glasgow Division CID, said: “McHugh was a member of one of Scotland's top-tier organised crime groups.

"I welcome his conviction and sentencing as disrupting the activities of these criminals remains a priority for our officers and underlines our commitment to the country’s Serious Organised Crime Taskforce.”