The Labradors and handlers visited several town centre pubs and nightclubs to search anyone detected to have a scent of illegal substances, and although no one was caught on Friday, three were cautioned on Saturday night, with the other due in court early in the New Year.

A 23-year-old Newbury man, a 20-year-old woman from Marlborough, Wiltshire, and a 20-year-old Thatcham woman were all given adult cautions for possession of cocaine.

A 26-year-old Newbury man was arrested for possession of cannabis and he has been bailed to appear at Newbury police station on February 2.

Sgt Shane Cooke, from the Newbury town centre team, who led the operation said: “Using the dogs is a very good operation that the licensees fully support – they do not want people in their premises who are taking illegal substances.

“The dogs are a very good deterrent and although not a lot of people got caught, the message quickly got around through mobile phones that it was not safe to bring illegal substances into the town centre.

“The dogs did detect drug scents on a few people other than those arrested, but they had taken substances earlier in the evening and did not have anything on them when they were searched.

“The four who were found with illegal substances were not only arrested but they now face not being allowed into any licensed premises in the town centre for a year as Pubwatch bans anyone who has been caught with drugs.”

Sgt Cooke and his team plan to use the dogs again in the New Year. No dates have yet been confirmed for their deployment and they will not be published for security reasons.

Sgt Cooke added: “The dogs are a great tool in the fight against drugs in nightspots. We hope that revelers take note that we are proactive and will not tolerate drugs in the town centre, or anywhere else for that matter.”