120 pieces of Oxyrhynchus papyri missing from EES collection

About 120 pieces of Oxyrhynchus papyri have been identified as missing from EES collection so far:

The following statement was provided to members of the EES during the Society's AGM on 16th November 2019:
Chairman’s statement to EES membersInvestigation of the Society’s collection of papyri from Oxyrhynchus, which is estimated to hold some half a million fragments, has to date identified around 120 pieces which appear to be missing, almost all from a limited number of folders; it is possible that a few more cases may emerge. So far 13 of the missing pieces have been located in the Museum of the Bible in Washington and another 6 in the collection of Mr Andrew Stimer in California, and both collections are returning these texts to the EES. The EES is working with the University of Oxford and the police to establish how the papyri located in these and any other collections came to be removed and sold. While the police investigation is in progress, the EES cannot comment further on these matters, but will report on developments as and when it is possible. [...] The EES is also working with Oxford University to enhance the current accommodation of the collection and to determine how best to ensure its care and publication into the next generation.  

So somewhere out there in the market (unless the person/persons who took them is/are still hanging onto them, or have destroyed the evidence)  are somewhere in the region of one hundred (plus?) stolen artefacts.  Which other collectors have recently bought some papyri? Were any of the eBay papyrus sales that observers have been documenting in recent years from this theft? Hopefully a full police investigation will make this clear.

What you will note is absent from that statement is any indication when the last thorough inventory was undertaken. In relation to what state, from when, did those pieces go missing?  Perhaps the latest movements of objects from the collection are just the last of a series going back episodically over a period of time? I would like the EES to not shield themselves behind some "ongoing investigations" excuses for proper transparency about the material they are entrusted (I use the word deliberately) with.