Thank you guys for replying. I contacted all the Facebook relatives I could find and only his brother replied at the time. It was sympathetic and then shortly after seemingly discoveri g what his brother had done, decided not to contact us again. They are all based in New Zealand so apart from messaging them, I was powerless to do much else.
I also have his addresses and visited each one. One was vacant woth the neighbours say they had left for New Zealand (but I since hear he is back and trading). the other two had tenants who flatly refused to speak to me or to even confirm they knew who he was. I believe at the time the police had also visited which is possibly why they decided not to speak to me.
Am going to restart the Facebook campaign I think. I have to find the line between innocent enquiry and harassment which I certainly don't want to be accused of!!