If the Police had any reasonable grounds to suspect that you had committed this offence you would have been arrested. Once arrested your house can be lawfully searched and any evidence (or suspected evidence) of any offence(s) taken away.

As this didn't happen you clearly have nothing to worry about. However the Officer's attitude (as described) is appalling and does need addressing by way of a polite but formal letter to the Chief Constable.

If you don't want to bother with a letter for your own purposes, please do it for the sake of the sport.