Hi Newjudge thanks for your response. Just to update & to help anyone ever in the same situation.
I emailed the police directly stating that I wish to raise a critical concern regarding the validity of the allegation. Due to the fact that the camera had not been validated within a year, it could not accurately measure my speed.
I quoted the annual calibration requirement stipulated in Section 2.1 of 'A Guide to Calibration Requirements for Traffic Enforcement Equipment' which states "that traffic enforcement devices undergo a complete calibration process annually, with any intervening maintenance followed by rigorous functional checks to affirm the device's accuracy" & asked if they could review the allegation, and in light of fairness & justice reconsider and ultimately dismiss the offence.
They responded back within a week and cancelled the speeding offence based on a device error.