I have a horrible feeling that this falls between the cracks of Strata law and civil law (and I'm hoping a real lawyer will put me right if I get this wrong).
The developer has basically “stolen” power from the Owners Corporation but it might be hard to get a criminal charge to stick. Instead I would present him with a bill and invite him to agree in writing that it be added to his unpaid levies (as an alternative to prosecution).
Then use a reliable and experienced strata debt recovery firm (or lawyers who do this kind of work) and make sure you get a court order that means when he sells his apartment, the OC gets first bite of the cherry before the proceeds disappear. This can be done at no cost to the OC but it's essential you do this before he sells.
If he refuses to play ball, then establish this as a separate debt to the Owner's Corporation and pursue it by the same means.
I hope that's the best advice – anybody out there who KNOWS the best way to handle this?
JimmyT