Humberside Police is urging residents to help stop drug dealers across Hull as festive celebrations continue.
Chief Inspector Dave Houchin said: "If you believe someone is taking mephedrone, please encourage them to contact a drug treatment agency. It could be the best Christmas present you ever give.
"If you suspect someone is dealing, please tell us and we may be able to give someone an extra surprise over the festive period."
Officers and staff in Hull held a week of action in October, which supported on-going work being carried out in schools, colleges and in the wider community, which targets criminals, but educates people on how mephedrone, also known as M-Cat, and other substances can have a detrimental effect on not just the user's lives, but also the loved ones around them.
Operation Trafford, which uses sniffer dogs to find drugs on people in pubs and nightclubs, is set to continue until the end of the month.
