The spontaneous emission rate properties of diamond nitrogen-vacancy (NV) centres are largely dependent on the hosting material, especially in nanodiamond. Inside a nanodiamond the fluorescence emission dramatically deteriorates as compared with the case where the defect is embedded in single crystal diamond. In addition the nano-environment, i.e. the hosting nanodiamond, can modify the spontaneous emission properties. It is important to study and identify the mechanisms responsible for these modifications to eventually employ the defect as a sensor of local density of states or to achieve emission enhancement. In this work, we summarize our approach to separate the electromagnetic effects, inducing radiative modification in the spontaneous emission of NV, from other non-radiative effects, these last leading to the quenching of NV emission. We also observe blinking which may be associated with photo-induced charge fluctuations by these additional non-radiative decay channels.