In the prison what is supposed to happen is that if someone is seen as a potential risk, they are asked.... In every case that I'm aware of, if somebody is believed to be carrying drugs, the police will be called immediately. The person will be detained and the police will then deal with it. If they're asked to be strip-searched, it generally means they don't have sufficient evidence. Maybe somebody's called in or informed on someone and then the person is supposed to be given the option of either proceeding with the strip search or leaving.
On October 4th, 2011. See this statement in context.