The Spanish prosecutor claims the Real Madrid forward knowingly used a business structure to allegedly hide his image rights income in Spain between 2011 and 2014.
The Portugal captain has been accused of four counts of tax fraud relating to the image rights payments.
However, Ronaldo's management company Gestifute have denied the allegations and said: "There is no tax evasion scheme.
"There has never been any hiding nor any intention to hide anything."
Ronaldo is angry at the way he has been treated by the tax authorities and has told Real he wants a move because he does not want to play in Spain any more.