Property Law - Australia:

A client, Dennis, a developer has recently purchased two vacant land blocks of land beside each other in a newly subdivided area. He commences building two twon house for investment purposes. There is a vacant block beside the blocks he is developing and to make it easier to work on his own sites, equipment and materials are stored on that site. Sometimes it is also used as a car park by his workers. Dennis has now received a letter from the owner of the cant block threatening legal action against him.

Explain to Dennis the likely nature of the legal action, why he may be liable and the possible consequences. (Cite law and cases where possible)