I suspect your original contact with the police would have been down to ANPR related "intelligence". Most of the major crimes in the area I live in seems to be committed by Liverpool scum bags who appear to commute. Intelligence gathered from ANPR could have highlighted your car as being dislocated, so possibly either stolen, cloned, or on regular crime away days.
Giving false information to your insurer leaves you open to being done for fraud, and I'd be surprised if they'd refund your premiums.
I've had the dubious pleasure of experiencing this the other way round. My insurer changed information I'd given them, and refused to correct their errors, even when I elevated my complaint to CEO level. I took my case to the FOS, won it, had all my premiums refunded plus compensation on top.