The investigation was opened after the Spanish tax authorities informed the Public Prosecutor's Office about perceived discrepancies in the data, with a Madrid judge now set to determine the next stage of the process.

However, Mourinho's representatives Gestifute Media issued a statement on Tuesday evening saying their client had "not received any notification" of the actions by the authorities in Spain, as well as circulating a copy of an official tax document dated July 3, 2015 which covered the periods in question.

Mourinho guided Real Madrid to the 2011/12 LaLiga title, returning to manage Chelsea after leaving the Bernabeu in June 2013 before taking over as Manchester United boss last summer.

"Jose Mourinho has not received any notification with regards to the news published today. To this date, neither the Spanish tax authorities, nor the public prosecutor have contacted Jose Mourinho or his advisers who were hired for the inspection process," the statement from Gestifute Media read.

"Jose Mourinho, who lived in Spain from June 2010 until May 2013, paid more than 26 million euros in taxes, with an average tax rate over 41 per cent, and accepted the regularisation proposals made by the Spanish tax authorities in 2015 regarding the years of 2011 and 2012 and entered into a settlement agreement regarding 2013.

"The Spanish Government in turn, through the Tax Department, issued a certificate in which it attested that he had regularised his position and was in compliance with all his tax obligations."

Spanish authorities have also recently filed papers against Real Madrid star Cristiano Ronaldo, who is accused of evading tax of some 14.7m euros (£12.8m) by hiding income from image rights.

The Portugal forward has strenuously denied the allegations and threatened to quit the country.

Last year, Barcelona forward Lionel Messi and his father Jorge were found guilty of tax evasion on the Argentina international's image rights, with more than 4m euros (£3.52m) owed in back payments.