Failing to file a s210C return on time (or within 15 working days of the deadline) without reasonable excuse is a corrupt practice, punishable by two years imprisonment and/or a $100,000 fine (sadly, the donations aren't forfeit). In the past the police (as opposed to the SFO) have generally refused to enforce the law (its not "real" crime, you see, unlike someone smoking a joint or walking while brown). But given the party involved and the police's culture of racism and subservience to power, maybe we might finally see the law enforced this time, though for entirely the wrong reasons.
I want the law enforced - donations fraud is a serious crime against our democracy, which undermines faith in our political system. But I want it enforced against everyone, powerful and powerless alike, and for the right reasons. The police's culture and past practice contaminates their actions in this case, and its just another argument of taking prosecution of electoral offences off them and giving it directly to the Electoral Commission.