More good reads:
https://www.goodreads.com/topic/show/1962418-princess-diana-accidental-death-or-murder-poll-58-of-you-say-murder
"Diana’s former butler Paul Burrell stated the Queen had once warned him, “There are powers at work in this country of which we have no knowledge”. Burrell also told an inquest in 1998 that an unnamed British royal had once warned Diana, “You need to be discreet, even in your own home, because they are listening to you all of the time”."
…and…
https://bbsradio.com/cgi-bin/webbbs/webbbs_config.pl?md=read;id=16957 contains the same as your post.