A couple of months ago saw our back neighbour spraying pesticide with a long thin tube directly on 2 of our trees, a 23 year old Pittosporum and a 23 year old Bottlebrush. He was spraying the trees directly at about 3 metres high above the ground. I could see his arms reaching up over the boundary fence with the long thin tubes and spraying one and then the other. These 2 trees have now died. About 9 nine years ago we had seen the same neighbour spraying our trees and my husband had spoken to him over the fence and told him to stop spraying our trees. So I sent him a letter last week saying we saw him spraying our trees again on so and so date and that now 2 of our trees have died and that his behaviour is not appropriate and very concerning to us. I wrote that instead of our beautiful trees we can now see his double storey house, his big water tank and shed instead. (We had planted those trees for screening when we knew his Double Storey house was being built so close to us) Wrote we are very upset that our Bottlebrush and Pittosporum have died, and that the spraying must stop immediately. Also wrote that my husband had already told him over the fence some years ago to stop spraying when we had just seen him spraying. We received a note in the letterbox from him saying that he was not spraying our trees but he was spraying a creeper that was "choking" our trees. He also wrote that he does not remember the conversation over the fence when my husband had told him not to spray our trees as soon as we had just saw him spraying our trees. We are extremely upset and concerned that we lost 2 of our trees, and we are now concerned about the other 3 trees we have next to the 2 that have died. We originally had planted 3 Bottlebrushes and 2 Pittosporums to screen a bit his huge house so close to us. I am sure he has been spraying our trees behind our backs at other times, as we had noticed our 2 trees that died had been deteriorating for a while. What can we do to stop him spraying and killing all our trees? Can we ask him to pay for the damage he did, that is, to remove the 2 that died and plant new ones? Thank you.