Drug dealers often take over the home of a vulnerable person to run the drug line from - this is known as cuckooing.

Officers are visiting landlords, letting agents and taxi firms to talk about how they can look for vulnerable victims and they are working with British Transport Police to display posters at train stations and on trains.

They are also visiting schools and children's' homes to talk to staff and youngsters about the issue.

Detective Inspector Matt Croome, who is part of the force's dedicated County Lines Disruption Team, said: "These gangs recruit vulnerable people and send them, often with a package of drugs, to deal elsewhere in the country. They are using the rail network and unknowing taxi firms to transport these people and we want raise awareness of this.

"We are also speaking to landlords as they may find their properties used in cuckooing, or discover vulnerable young people staying at a house which they were not aware of.

"If you suspect something, please call us on 101 or contact Crimestoppers on 0800 555 111. You could help safeguard someone too vulnerable to help themselves."

Taxi drivers are being urged to look for these signs:

Is your passenger a child, sometimes as young as 12, and travelling alone?

Are they travelling during school hours, or unusual hours for a youngster to be away from home, such as early morning or very late at night?

Are they unfamiliar with the local area or do they have an accent which is not local?

Are they travelling a long distance?

Are they paying for these journeys in cash?

Landlords are encouraged to look for these signs:
Does your tenant appear to be rich but they want to rent an inexpensive property?

Are they unable to provide landlord or employment references?

Do they prefer to pay rent in cash without good reason?

Do they stop you from inspecting your property when given reasonable notice?

Train drivers and those who regularly travel by train are urged to look for these signs:
Have you seen a child, sometimes as young as 12, on the train alone?

Are they travelling long distances?

Are they travelling during school hours, or unusual hours for a youngster to be away from home, such as early morning or very late at night?

Do they travel on the same route on a regular basis, like once or twice a week?

Are they receiving an excessive number of texts or phone calls?

Are they with someone older who is buying their tickets or giving them money for tickets?

Are they deliberately avoiding authority figures, such as police officers or railway staff?

If you suspect someone is involved in County Lines, or a property has been cuckooed, contact us or Crimestoppers. » Less