Border security in oz

[NinOz]

Just had a sound decoder delivered.  After opening, I noticed it had two stickers on the parcel.  One said opened by Biosecurity Australia and the other said Released by Biosecurity.  Why would biosecurity hold and open a parcel which only contained paper and non-biological matter?
My wife noticed the customs declaration seemed to say it contained "model ham accesories", a badly written "train" looks like "ham". 
Perhaps the parcel packer just finished a salami sandwich and the lingering odour caught the attention of a detector dog.
Never had this happen before.  Have had RC model aircraft glow plug engines opened and dismantled to inspect internals for drug concealments (came from Honkers) by customs.  But biosecurity?

[RailGooner]

I'll look out for your parcel making an appearance on a future episode of 'Nothing to Declare' (Sky Witness channel).