The economic crime arm of Madrid's Provincial Prosecutor's Office filed a complaint on Tuesday against the Portugal worldwide for allegedly committing four crimes between 2011 and 2014. It added that Ronaldo falsely claimed the income as coming from real estate, which "greatly" reduced his tax rate.
The operation is taking place at a European scale, with several tax authorities looking for traces of fiscal fraud in football.
"The Prosecutor's Office says that the player declared the income derived from the transfer of image rights as income from movable capital to evade taxes".
Additionally, the prosecutor said Ronaldo "intentionally" failed to declare income of 28.4 million euros linked to the sale of his image rights from 2015-2020 to a Spanish company.
"The laws applicable to Cristiano Ronaldo are the Personal Income Tax Law and the Impatriots Law".
The world's highest-paid athlete is the latest target of tax authorities who have probed a number of other high profile footballers including FC Barcelona forward Lionel Messi who was sentenced a year ago to 21 months in prison for tax evasion.
However since both men have no prior criminal history and the sentence is below 2 years, they will spend no time behind bars.
The Spanish club said it has full confidence in the player and 32-year-old forward will prove his "total innocence".
Ronaldo reportedly earned $93 million past year in salary, endorsements and other bonuses. The Portuguese forward scored 42 goals in all competitions this season, including two in the Champions League final as Real became the first team to retain the title.