Fever nightclub in High Street was evacuated in the early hours of Sunday morning.
Police were called at about 2.45am on Sunday following a report that a CS canister had been deployed, and that a number of people were feeling ill effects.
Police have said the nightclub was evacuated while the air conditioning dispersed the substance, and that it was re-opened shortly before 3am.
A statement from the police said: “Warwickshire Police and the licensee are working together to determine the circumstances of the incident. No-one suffered long-term ill effects and the canister was not recovered. No-one was arrested.”