Prosecutors have accused him of defrauding the Spanish tax authorities of €3.3m (£2.9m), according to a report in El Pais.
The news comes a week after fellow Portuguese star Cristiano Ronaldo was charged over tax fraud. He has since denied the allegations.
The complaint came from AEAT, the Spanish tax authority, which claimed the Portuguese player defrauded €1.4m in 2011, €1.7m in 2012, €3.2m in 2013 and €8.5m in 2014. He could face a jail sentence of between one and five years.
Earlier this year a 21-month jail sentence handed to Barcelona striker Lionel Messi was confirmed by Spain's Supreme Court.
The Argentinian star and his father Jorge Messi were both sentenced in July last year after being found guilty of three counts of tax fraud.