I never heard of it before either. But somehow it sounds like something that might be true considering the context. After his death there was a small rift between the family and Sandow's friends wrt how he died. The friends just said it was suicide, simple as, and refused to go into it any more. So something had happened. Did he message his friends before, was there a note? If that story is true it might be a reason for the family to say it was heart failure.
England isn’t a big country & London isn’t a millions miles away from where I live , add in that Olympia level bodybuilders are very few + knowing a lot of competitors & judges here + people talk.
It’s not a big inner circle. I cannot 100% confirm that story yet as factual - Though those that I know who are close to Hollingshead who found him say it is.
I know James though not well enough / close enough to ask such questions.