Make sure you have evidence of a motion passed at a general meeting, if you did not authorise the strata manager to issue such notices.
This would be a motion to delegate the committee to act on behalf of the owners corporation – a standard motion at most (but not all) AGMs.
There are laws about “abandoned goods”.
I had a look at these too. They are generally about stuff left behind by residents who have moved on. I don’t think they would apply here.