Mystery return/delivery

Well this is a bit of a strange one. Today, I received a padded mailer in the post. It was scanned and handed to me. Upon receipt, the first thing I noticed was the end was open. It had obviously been cut the entire way across with scissors.

So I took out the contents. It was a 6× DVD television series. This is not something that I've sold, or even ever listed. Nor did I purchase it.

Obviously the next step is to check the sender. It has my return address stamp in the sender's details area. So I immediately look at the front and see 2 concession postage stamps. The original address label has been half torn off, and the remaining details have been blacked out. There is a scrap of paper with a hand written name (which I don't recognise) loosely taped to the mailer by one edge, and a Parcel Post tracking label.

Some seller is obviously too cheap to outlay about 10c each to purchase padded mailers, so they're recycling used ones - and haven't bothered updating the sender's details. I assume it was done to recycle the uncancelled stamps and skimp on postage.

It was delivered to me as RTS because it had no address on the front, and I have no idea who sent it, or where it was meant to go. The AP tracking says sender's details not available.

The only thing I do know about this mystery item, is that the mailer was originally shipped by me between August 25 and October 13. I don't even have any idea what the original contents were.

I took it to the police station to hand it in as lost property, but they refused to take it. They said that because I am the sender, it is legally mine.

I don't know what more I can do, but I do know that some poor buyer out there won't be very happy when their item doesn't show up, yet the tracking shows that it was delivered today.