Lionel Messi and Javier Mascherano, among others, have already been convicted.

On Tuesday, Ronaldo was told to appear in court on July 31.

Ronaldo, who is in Russia at the Confederations Cup with Portugal's national team, has played in Spain for Real Madrid since 2009.

The cases are about the profits made from image rights, not salaries from their clubs.

Both Ronaldo and Mourinho are represented by Portuguese agent Jorge Mendes.

Atletico Madrid striker Radamel Falcao and Real Madrid defender Fabio Coentrao, who have also been accused of tax fraud in Spain, are also clients of Mendes.

Last week, Ronaldo was accused by a state prosecutor of four counts of tax fraud totalling 14.7 million euros (£12.9 million).

The Portugal forward is now under official investigation and will have to appear in the Pozuelo de Alarcon Court No 1 on July 31.

A judge will then decide if there are grounds to charge him with a crime.

The prosecutor said last Tuesday that there was evidence that Ronaldo used a shell company in the Virgin Islands to hide the money he had made from image rights.

Ronaldo has denied any wrongdoing.

The accusations against Ronaldo have caused speculation in Portugal and Spain that he is now considering leaving the country to play elsewhere.

The summoning of Ronaldo coincided with the same Madrid-based prosecutor's office accusing Mourinho of two counts of tax fraud.

A statement issued by the section for economic crimes of Madrid's provincial state prosecutor's office said its investigations indicated that Mourinho committed tax fraud in 2011 and 2012.

The prosecutor based the accusations on information provided by Spain's Tax Office, which appear to show that Mourinho used shell companies in the Virgin Islands and Ireland to "hide profits made from image rights".

It will now be up to a judge to decide whether to take Mourinho to court.

Last year, Messi and his father, Jorge Horacio Messi, were found guilty on three counts of defrauding tax authorities of 4.1 million euros (£3.6 million) from income made from image rights.

The two were given 21-month jail sentences but neither is expected to serve prison time since it was a first offence and the sentence was under two years.

Mascherano was also convicted of tax fraud last year and was given a suspended one-year sentence.