Jose Mourinho's advisers have hit back at accusations that the Manchester United manager failed to pay millions of euros in taxes to the Spanish authorities during his time in charge of Real Madrid.

The 54-year-old Portuguese, who coached Madrid from 2010 to 2013, has been accused of "two offences against the public treasury", the prosecutor's office said in a statement on Tuesday.

They claim that Mourinho, who took over at United last year, failed to declare 3.3 million euros ($3.7m, £2.9m) during his time in the Spanish capital -- 1.6 million euros in 2011 and 1.7 million euros in 2012.

But a statement released by Mourinho's representatives Gestifute Media said he had not been informed personally of the accusations.

They also circulated a copy of a tax document dated July 3, 2015, which covers the period in question.

According to Gestifute, Mourinho "paid more than 26 million euros in taxes, at an average rate above 41 percent and accepted regularisation proposals from the tax authorities in 2015 relating to the years 2011 and 2012, and resolved by agreement his situation for the year 2013".

The statement also said that Mourinho had received a certificate from the authorities confirming that he was "up to date with all his tax obligations".

The accusations come as Madrid superstar Cristiano Ronaldo was summoned to appear before a judge next month, accused of tax evasion of 14.7 million euros.

The 32-year-old Portuguese star is facing four charges of fraud through offshore companies between 2011 and 2014 and will appear before a judge on July 31, judicial sources told AFP.

The four-time world player of the year, who said last week his "conscience is clear", is threatening to leave Madrid over the affair, according to Spanish and Portuguese media.

Both Ronaldo and Mourinho are clients of football super-agent Jorge Mendes, who has been summoned to appear before the court at Pozuelo de Alarcon, just outside Madrid, on June 27.

Revelations from the whistleblowing website Football Leaks have lifted the veil on the practices supposedly used by Mendes to optimise often enormous earnings from image rights by his clients.

Media consortium European Investigative Collaborations (EIC) has claimed that no less than 185 million euros worth of income has escaped the attentions of tax authorities using shell companies and offshore accounts.