King Felipe of Spain has fled the country
The announcement was made by the Spanish royal family in a statement released this afternoon.
The former King said in a letter to his son, made public today: "Guided by my conviction I can offer the best service to Spaniards, its institutions and to you as King, I am communicating my decision to move away from Spain.
"It's a decision I am taking with deep feeling but with great serenity.
"I have been King of Spain for almost 40 years and during that whole time, I've always wanted the best for Spain and for the Crown."
"With affection as always, your father."
In June, Spain's Supreme Court opened an investigation into the former head of state's involvement with a high-speed rail contract in Saudi Arabia.
He reportedly received $100 million from the late Saudi King.
Mr Carlos, 82, has repeatedly declined to comment on the allegations.
The former Monarch abdicated from the throne in June 2014 after four decades on the throne.
After abdicating, his popularity dropped dramatically following rumours about lovers, corruption and Swiss bank accounts.
More to follow...