Parcel theft by Australia Post employee?

I recently has a package picked up at my LPO by someone else. The employee of the store remembered the transaction. This person had my full name, tracking number and home address. With this information, he was able to nominate himself as an alternative pick up person and collected the parcel.

Alarm bells for me started ringing when the LPO staff member showed me the computer screen of their internal portal and it had a signature that looks like mine and a proof of delivery photo of my front porch.

The photo had a section of it blacked out. I suspect it was a previous delivery and they blacked out the image of the old parcel. The signature looks like a scrappy one I did in a rush when I signed for a package. Again it was from a previous delivery.

I have footage from a home camera of my usual delivery driver attempting delivery on Friday morning but I wasn't around at them time to sign for it

It got me thinking, what is stopping a postal worker at the various sorting facilities from just taking a photo of packages that need signatures on deliveries and then monitoring them to see if was not able to be delivered? They could arrive first thing the next day and given the shipping label has all the details needed to nominate someone else to pick up, they could easily just take the parcel. I should add that the guy who stolen my package arrived at opening time (9am) the next day.

My local LPO has CCTV footage of the guy although it is from a bad angle. I do not believe that my LPO is behind this as they have been very transparent.

Should I contact the police? Or speak directly to Australia Post? The value of the item is not that much, but something like this is more about principle and how it can undermine the trust of the current postal system.