Investigators from the Supreme Court have launched another probe into the financial affairs of the former King, Juan Carlos.
The third inquiry by the Anti-Corruption Prosecutor’s Office focuses on payments made to a friend of the King by a Mexican businessman.
Investigators are examining details to see if there were any irregularities concerning tax payments made by any of those connected to the case.
The probe comes a day after another investigation was launched into the alleged use of a credit card by the King.
His financial affairs in connection to a high speed railway line in Saudi Arabia is also under legal scrutiny.
The emeritus King denies any wrong doing and is fully cooperating with authorities.