North Yorkshire Police says gangs in cities across the UK are coercing children and vulnerable people to transport, store and sell drugs in smaller towns, using dedicated phone lines.
Gangs also take over the homes of vulnerable people - with mental health or addition problems - and use them as bases for dealing drugs, in a practice known as cuckooing.
Detective Superintendent Fran Naughton told a public accountability meeting: “In the last 12 months, we have taken down six county lines. That means we’ve completely obliterated those drug dealing lines into North Yorkshire.
“We’ve disrupted another 13 significantly and got these drug dealers off track.
“Many of the tactics are overt, the public will see us stopping vehicles and potentially searching people and looking for drugs.
“But in order to take lines down and really disrupt them in the longer term, we do use covert tactics.”
Detective Superintendent Naughton revealed that in one month, officers working to tackle county lines drug gangs as part of Operation Expedite made 18 arrests, seized cocaine worth £7,550 and Cannabis worth £8,400, and found a range of weapons, including two replica handguns and four flick knives.
She said: “The people we arrest do tend to have a weapon of some sort to either threaten other gangs or for their own protection when they’re drug dealing.”
The last drug dealing phone line that was taken down by the force was known as the 'Danny line' and it was used to transport crack and cocaine from Leeds and Bradford to Harrogate.
Officers applied to Newcastle County Court for a Drug Dealing Telecommunications Restriction Order (DDTRO) in August.
Inspector Penny Taylor said: “These orders are a helpful disruption tactic to interrupt the flow of drugs. Police regularly seize mobile phones from suspected drug dealers, but the numbers and associated contacts can be reactivated within hours.
"The orders allow us to take down the line and remove the phone number from circulation permanently, meaning it cannot ever be reactivated on another device, depriving the dealers of the key means to sell their drugs.
“Drug dealing and the associated exploitation of vulnerable people is a foremost priority for North Yorkshire Police and we will continue to target dealers who prey on the vulnerable and cause misery in our communities.”