Chris,
I think the neighboring property is privately owned and does not appear to have an owners corporation established.
Diana,
Possibly one method of obtaining the owners details for the neighboring property you could try a freedom of information search at Council, but you may end up pulling up short with establishing everything relating to the building is sent to the real estate agent.
A complaint to Council or Sydney Water may save you some of the hassle of continuing to pursue the owners.
Good luck