A dog trained to sniff out drugs picked out a staggering 27 pub-goers and clubbers to be searched in Oxford city centre on Saturday night.

A team of police officers and a black Labrador called Benson carried out checks in St Ebbe's, George Street and Hythe Bridge Street.

One person was arrested for possession of Class A drugs and two on-street cautions were issued to people carrying cannabis.

Benson can detect people who have used or been in contact with drugs within the last 36 hours.

A number of people searched told officers that they had taken illegal substances in the last two hours.

During a previous patrol in August, Benson picked out 14 people to be searched on suspicion of carrying drugs in Park End Street and Gloucester Street.

Oxford city centre's Nightsafe manager Karen Crossan said: "Benson is trained to work through a static crowd and check large numbers of people within minutes. He indicates by sitting next to his handler if he can smell any trace of drugs on a person. They are then searched by the police officers. The public were very interested in our team and what we were doing and we had very positive feedback from them and the licensees."

Benson's handler Phil Munt, from Corporate Search Ltd, said: "We provide a high-profile and visual deterrent. By licensees assisting the team, they are seen to be taking reasonable steps to prevent drug misuse and, in doing so, protect their licence and their customers."

Insp Graham Sutherland, who is in charge of policing the city centre, said: "Using a passive drug sniffer dog provides support to city licensees and door staff with identifying possible drug dealers and users.

"It demonstrates the commitment of the Nightsafe partnership to the public and our desire to make Oxford safer and keep it safe."

Caroline van Zyl, the city council's executive member for a safer city, said: "This is another example of the partnership working in Oxford - which should be welcomed.

"Residents will be encouraged and reassured by the commitment and cooperation of licensees.

"They are welcoming measures to make our clubs and pubs cleaner and safer."

The Nightsafe partnership was set up to combat binge drinking and alcohol related crime.

Partners include Oxford City Council, Thames Valley Police, Oxfordshire County Council, Oxfordshire Fire and Rescue Service, city centre management company OX1 and Oxford City Primary Health Care Trust.