Five members of a network, which sold heroin and crack cocaine in one town, have been locked up.
The group were part of the so-called 'B' line, which made around 60 deals a day in Dover.
Some of the Dover drug dealing network with the cocaine
This was before its members were among 36 people arrested in early-morning drugs warrants last February.
It is estimated that the 'B' line supplied nearly 5kg of heroin and crack cocaine, worth around £300,000, to drug users between June 2019 and February 2020.
Three members of the group's hierarchy, as well as two street dealers, have now been jailed for their part in the conspiracy.
Last year officers from the Kent and Essex Serious Crime Directorate gained information that street dealers, including Paul Hunt and John Butterworth were selling heroin and crack cocaine through a phone line known as the 'B' line.
They were aided by a 16-year-old girl.
Officers carried out a warrant at a house in Folkestone Road on Thursday, January 23 this year and seized a phone.
This contained videos of the group's two main stockists, Jordan Wills and Abdul Jalloh, packaging up drugs for street dealers to sell on.
Jalloh and Wills were arrested during the execution of warrants in the town on Tuesday, February 4, along with Donna Mottershead who helped run the drug line between November and December last year.
The defendants have since admitted conspiracy to supply Class A drugs and at Canterbury Crown Court.
Abdul Jalloh, 33, of Folkestone Road, Dover, was jailed for eight years.
Jordan Wills, 25, of Coombe Valley Road, Dover, was jailed for five-and-a-half years.
Donna Mottershead, 24, of Folkestone Road, Dover, was jailed for three years and three months.
Paul Hunt, 52, of Auden Way, Dover, was jailed for three years.
John Butterworth, 28, of East Cliff, Dover, was jailed for two years and four months.
A 17-year-old girl from Dover was given a two-year Youth Rehabilitation Order.
DC Alan Poulton of the Kent and Essex Serious Crime Directorate said: "This was an extremely thorough investigation during which our officers identified and arrested numerous members of this network.
"Kent Police are determined to make the county a no-go area for drug dealing groups and I am pleased this long-running investigation has now seen more criminals brought to justice.
A total 53 suspected drug dealers have been arrested in Dover since February 2020 as part of the Kent Police operation.
A total 39 have since been convicted of or admitted charges, with 26 now serving prison sentences.
Six others brought to book after the February raids were sentenced earlier this year.
On March 11 Lewis Carney, of Maison Dieu Place, Dover, was jailed for four-and-a-half years. and Archie Foad, of Victoria Park, Dover, for two-and-a-half years.
Four others were sentenced on August 21.
Sarah Manser, of Clarendon Street, Dover, and Sarita Ripley, of William Pitt Avenue, Deal, each got four years' imprisonment.
David Murray, of Templar Street, Dover, was sentenced to five-and-half years and Richard Harvey, of Winnipeg Close, Dover,
got two years and four months.