King Juan Carlos's former mistress reveals she feared their relationship would destroy the monarchy… and how she was warned she could end up 'dead in a tunnel like Princess Diana'

The Danish businesswoman says threats were made by Spanish intelligence service. 'From the moment I came back from that trip I was under full-blown surveillance,' Ms Zu Sayn-Wittgenstein told the BBC. An anonymous threat was made about there being 'many tunnels between Monaco and Nice' - a reference to Princess Diana's fatal car crash. Furthermore, she claimed a book about the British royal's death was left out in the living room of her Swiss apartment.

https://www.dailymail.co.uk/news/article-8646639/King-Juan-Carloss-former-mistress-reveals-warning-end-dead-tunnel-like-Diana.html