Thanks everyone, Enviromental Health it is , I know he owns the house, when he got divorced his ex wanted the house sold but he got medical something or other to say it would seriously affect his health and should be allowed to stay, also I don't think it's getting him down he's a horder and can't throw anything away, he has about 30 broom handles in his conservatory, just in case, so I think if it all got sorted for him it would send him over the top again.
I do feel a right b***h doing this as he's helped me quiet a bit at times, when my kids were young and their dad had gone awol, my washing machine had packed up, the next thing I knew he'd got me a working second hand one to tide me over, and has lent me money in the past as well, but I just can't go through another summer with that smell