The so-called 'graft' phone number was used by a suspected county lines gang from the Merseyside area to tip off users about where to buy drugs in the seaside town of Grimsby.
Police say the number was used to direct users to locations where heroin and crack cocaine dealers could be found and where they could get drugs from.
As part of Humberside Police's Operation Hamilton, a Drug Dealing Telecommunications Restriction Order (DDTRO) has now been granted which switches off the number so it can't be used again.
It is the first time that such an order has been applied for by the Humberside force.
Detective Inspector Phil Booker said: “Basically, this number was used as almost a ‘call centre’. Drug users would contact it to make arrangements to buy drugs and be directed where to attend and at what time, to meet with the dealer.
“This was the main ‘graft’ line to a county lines gang member based in Merseyside who used the number to co-ordinate and facilitate the supply of heroin and crack cocaine in Grimsby.
“This DDTRO stops that phone number being used or reactivated.
“In the past when we have arrested a dealer and seized their phone, their number would usually be reactivated in another phone within hours. This order blocks a number which could be used again for drugs activity and other crimes.
“We’re not only disrupting the supply of drugs into our force area by doing this, we’re also disrupting the dealers drugs supply operation.
"Put simply if they can’t contact each other, they can’t deal drugs.”