The "mastermind" behind the "largest amount of cannabis brought into the Northern Territory to date" has been sentenced and jailed.

Giuseppe Romeo was the distributor in a drug operation between South Australia and Darwin that reeled in almost $2 million.

Prosecutor David Morters pushed for the 65-year-old to be hit with the maximum 14 year penalty, arguing he's a career criminal.

Giuseppe Romeo was the distributor in a drug operation between South Australia and Darwin that reeled in almost $2M. (9News)

Romeo's first drug conviction dated back to when he was in his 20's. The Adelaide man was extradited back in March 2018.

He eventually pleaded guilty in October 2019 to commercial drug supply.

Romeo helped distribute around 300kg of cannabis into Darwin from South Australia between July 2016 and March 2018 - profits totalling $1.8 million.

Using the likes of toll freight and the Grey Hound bus service, drugs were exported every fortnight over a 21-month period.

The "mastermind" behind "the largest amount of cannabis brought into the Northern Territory to date" has been jailed. (9News)

Romeo - the kingpin of the operation - organised, recruited men and paid them to deliver the cannabis across Darwin. He was sentenced to nine years jail, with a non-parole period of six years, four months.