Spain's Ex-King Juan Carlos Investigated for Alleged Corruption Six Years After His Abdication

King Emeritus Juan Carlos I of Spain — who abdicated from the Spanish throne six years ago — is being investigated for alleged corruption by the country's Supreme Court.

The probe into the 82-year-old former monarch was announced Monday by Spain’s Public Prosecutor’s Office and will delve into claims that the former king received kickbacks of up to $100 million for his role in an $8.5 billion Saudi rail contract awarded to a consortium of Spanish firms in 2011.

“This investigation focuses, precisely, on delimiting or ruling out the criminal relevance of the events,” reads a statement from the prosecutor's office in Madrid.

It adds that an investigative team led by financial specialist Juan Ignacio Campos will specifically look at whether the former monarch was involved in criminal activity after his abdication in 2014 and was therefore not covered by the immunity granted to the country's Head of State.

"It is necessary to carry out new proceedings that directly affect the King Emeritus,” adds the prosecutor's statement.

Spain's Zarzuela Palace has yet to respond to PEOPLE's request for comment.

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The former king officially withdrew from public life in May 2019. On March 16 his son, King Felipe VI, took the historic step of renouncing his family inheritance in a public attempt to distance himself from the financial scandals swirling around his father.

Within a lengthy statement from the Zarzuela Palace, Felipe announced that in order “to preserve the exemplar nature of the Crown,” he had decided “to renounce the legacy of Don Juan Carlos, which could have come back to him personally.”

At the same time, the palace also announced that Juan Carlos would no longer receive his annual pension of $215,000.

The ex-monarch, who attended the wedding of Rafael Nadal on the Spanish island of Majorca in October 2019, is also the focus of a probe by Swiss financial authorities into the $100 million payments, which are alleged to have been paid through an alleged offshore account, named as the Lucum Foundation, based in Panama.

Reports in the Swiss-based Tribune de Genève newspaper claim that the funds were initially deposited in the Swiss Mirabaud bank. Then, in 2012, $73 million of it was allegedly transferred to an account owned by Juan Carlos' alleged mistress, German-born businesswoman Corrina zu Sayn-Wittgenstein, 55.

In a further twist, Sayn-Wittgenstein is herself taking legal action through the British courts, alledging harassment from the Spanish intelligence services over her intimate knowledge of the ex-king's financial dealings.

Prior to Juan Carlos’s withdrawal from public life last year, the Spanish monarchy also endured another financially-related embarrassment when King Felipe’s brother-in-law was sentenced to five years in jail for embezzling money from a charity in Majorca.