University students have faced "rampant intimidation" from drug dealing gang members, it has emerged.
Minutes of a Crimestoppers meeting said University of Northampton students were being targeted by dealers from "larger metropolitan cities".
Police said officers were acting on concerns over "drug-related anti-social behaviour" at a halls of residence at the university.
A university spokesman said "criminal activity will not be tolerated".
The Crimestoppers meeting in January included an update on "county lines drug dealing" from Det Insp Tony Hopkins, of Northamptonshire Police.
'Set up and sell'
In the minutes, seen by the BBC, Mr Hopkins described county lines as a "phone line that is used for the purchase and sale of drugs".
He said the drugs often come "from larger metropolitan cities and are distributed in to smaller market towns".
The practice works, according to the minutes, by young or vulnerable people being sent to smaller areas to "find somewhere to set up and sell the drugs".
Mr Hopkins said these people will often find a place where they can stay in the targeted town, including taking over another person's property - a practice known as "cuckooing".
The minutes added that concern was expressed county lines dealing was a "UoN problem" and "halls of residence intimidation rampant".
A police spokeswoman said the force has been "working closely with the University of Northampton after concerns were raised about drug-related anti-social behaviour at the St John's hall of residence".
She said two search warrants had been executed at St John's on Thursday.
In relation to that investigation, a 20-year-old man was arrested on suspicion of being in possession of Class B drugs with intent to supply.
Earlier this month, Northamptonshire Police issued an appeal to tackle the "increasing problem" of cuckooing.
Det Insp Dave Harley said it has become common for gangs to "take over addresses of vulnerable adults by force".