The former king of Spain, Juan Carlos I, used his alleged lover Princess Corinna zu Sayn-Wittgenstein to buy multiple overseas properties due to her tax residence in Monaco, according to claims made by the German aristocrat in a leaked audio recording.

In a 2015 conversation with a former Spanish police officer in London, Princess Corinna alleged that the king’s lawyers put her name on overseas properties without her permission, complaining that she was being drawn into “money laundering”.

The 53-year-old princess, who obtained her title from her second marriage, also claimed that Juan Carlos I held bank accounts in Switzerland in the name of his cousin, Álvaro Orleans de Borbón.

The allegations in the recording, published by the Spanish newspapers El Español and OK Diario, are the latest controversies to spring from the long-reputed relationship between the Monaco-based princess and Juan Carlos I, who has an estimated fortune of up to €2 billion.

The aristocrat, an adviser to Prince Albert of Monaco, was named in the Spanish press as the then king’s lover after she was discovered in his company when he was injured during a secret 2012 elephant hunting trip in Botswana.