So anytime the police were involved, then those occasions would show up on an enhanced CRB, provided they recorded your details correctly at the time. And if you apply to be registered by the ISA then an enhanced CRB will be run.
If the O.P. was not arrested (i.e. detained due to suspicion of involvement in a crime), accused of a crime, or charged with one then surely the Police cannot justify passing on information about his/her section 136 detention to a prospective employer.
The whole point of an 'enhanced criminal records check' is to detect involvement in crime which didn't result in a conviction, not to pass on irrelevant defamatory information.
Perhaps the O.P. should apply for a job which will require an enhanced check and if this information is passed on s/he could kick up a fuss about it and get the Police to change their policy...