//Given that the events were over a year ago and theres sometimes no definite proof of who was there who was in the room rather than working in the office above, how long they stayed etc theres sometimes a need for the questionairs//
Why so? If the police have no proof that an offence took place, how is sending a questionnaire to the alleged offender going to help (unless he's dopey enough to admit the offence)? If I was suspected of committing an offence and I knew I'd done so, but no proof existed, I'm hardly likely to help the police with their enquiries, am I? If one was sent to me I would suffer a memory lapse, decline any fixed penalty if it was offered and put the prosecution to proof in court.
The entire business is a complete farce. Evidence to support a prosecution should be available when a fixed penalty is issued. It would be an abuse of process to offer somebody suspected of a criminal offence a fixed penalty when there was no realistic prospect of a conviction. If all the police have is responses to their questionnaires then the recipients of those questionnaires have only themselves to blame for providing the police with the material to prosecute them.