A former lover of the former king of Spain believes a book about the death of Diana, Princess of Wales was left in her home as part of a campaign of harassment directed by the monarch, the high court in London has been told. The former king Juan Carlos is seeking sovereign immunity at the court against claims he used Spain’s spy agency to harass a Danish businesswoman, Corinna zu Sayn-Wittgenstein. In a skeleton argument presented to the court, lawyers for Sayn-Wittgenstein said she was seeking damages for the “great mental pain, alarm, anxiety, distress, loss of wellbeing, humiliation and moral stigma she has suffered.” After her five-year affair with the king, his “associate” Gen Sanz Roldán, then head of the Spanish national intelligence agency, and his colleagues began “threatening her and her children”, the document claims. The threats began when Roldán met Sayn-Wittgenstein at London’s Connaught Rooms in 2012, two years before Juan Carlos abdicated the Spanish throne and his son Felipe became king. While the London meeting was taking place, Sayn-Wittgenstein’s apartments in Monaco and a villa in Switzerland were broken into, she claims. She later discovered a book about Diana’s death had been left on a coffee table at the Swiss villa, the document states. Papers at the apartment had allegedly been “disturbed”. Her lawyers argued that the harassment continued after the abdication, including a surveillance operation against her home in Shropshire. This involved drilling a hole into her bedroom window in June 2017, and gunshots being fired at CCTV cameras at the property in April 2020, the document says. Both incidents were reported to police. Sayn-Wittgenstein claims that at the time Juan Carlos was demanding the return of gifts he had given her when they were lovers, including art, jewellery and £65m in cash, the skeleton argument says. Her lawyers argued that sovereign immunity did not apply because much of the harassment occurred after the abdication, and in any case was “quintessentially private in nature”. Defending the former king, Daniel Bethlehem QC said in written arguments before the court that the former king “rejects the allegations made against him, and any alleged wrongdoing by the Spanish state is denied in the strongest of terms”. He argued sovereign immunity should apply because the only way Juan Carlos could have persuaded officials from Spain’s intelligence agency to act on his behalf was because he either was or had been king. Juan Carlos’s actions were “quintessentially public acts because of who the person is”, Bethlehem told the court. The former king’s defence, submitted to the court, said: “Many of the acts underlying the claim against His Majesty can be considered to have been done in his public capacity. The claimant refers to His Majesty using the head of the Spanish national intelligence agency, ‘agents and/or agents or contractors’ of the intelligence agency and other ‘operatives’ to conduct physical and digital surveillance and ‘trespass’ on her property. Such alleged conduct, even if abusive or unlawful, would have been in His Majesty’s official capacity.” Bethlehem also argued that immunity should continue to apply after his abdication because Juan Carlos remains part of the royal household and a key figurehead in the Spanish constitution. He told the court: “His majesty is an essential part of the constitutional fabric of Spain. This remains the case after his abdication. His majesty is not only the personal embodiment of the return to democracy in Spain, but also an unbroken connection to the past.” James Lewis, QC, for the claimant, said: “A former head of state has no immunity.” The hearing before Mr Justice Nicklin continues.