Police in Surrey plan to send plain-clothed officers into pubs and clubs in three "problem" towns to combat incidents of antisocial behaviour and violence in public places.
The plan to post officers in venues in Walton-on-Thames, Weybridge and West Molesey is being instigated by Inspector David Hollingsworth — the new police chief in the borough of Elmbridge.
Hollingsworth said undercover officers would visit venues "where we believe the problems are".
The visits will also be made "as a general tool to make sure everything is in place".
He said officers will co-operate with — and inform — "good" licensees of their presence, but would act covertly in potentially more problematic venues. "Some of the venues are quite big and licensees and security staff sometimes can't see everything that is going on."
Hollingsworth added it was a case of identifying problems and working with licensees to resolve issues.
The Morning Advertiser's legal expert Peter Coulson said: "It is possible for plain-clothed officers to visit any kind of retail outlet undetected, but they would have to produce evidence of wrongdoing by the licensee or staff to take action against the licence.
"Some trade bodies consider this to be 'spying', but it is common in all aspects of police work."