The 50-year-old is one of the most high-profile names revealed in the 'Pandora Papers', an investigation by the International Consortium of Investigative Journalists, which has seen 11.9 million leaked documents released this week.
It has been alleged that Guardiola had a current account open in Andorra until 2012, when he took advantage of a tax amnesty in Spain to regularise his finances. Until that point, he had not declared the funds held in the account to the Spanish Tax Agency.
Manchester City boss Pep Guardiola has been named in the 'Pandora Papers' investigation
It is alleged Guardiola (left) held his wages from Qatari club Al Ahli in an off-shore account
They are leaked documents showing how 35 current and former world leaders - including associates of Vladimir Putin - as well as other famous names from a variety of different backgrounds, used accounts in tax havens to accrue huge amounts of wealth and carry out transactions.
The files consist of 12 million documents from 14 financial services companies in countries including the British Virgin Islands, Panama, Belize, Cyprus, the United Arab Emirates, Singapore and Switzerland.
They were obtained by the International Consortium of Investigative Journalists (ICIJ) before being studied by more than 650 reporters from BBC Panorama, the Guardian and more than 100 other news outlets.
The papers follow four other huge data leaks in the past seven years - including the FinCen Files, the Paradise Papers, Panama Papers and LuxLeaks.
Reports in El Pais and La Sexta claim that Guardiola opened the offshore account to deposit wages from his two years playing for Al Ahli in Qatar, where he was being paid in the region of £1.7million a year from 2003 to 2005.
The now-Man City boss is reported to have set up the account through the creation of a shell company called Repox Investments, depositing his salary into the Andorran account, where he did not have to pay tax.
Guardiola's legal advisor Lluis Orobitg has explained that the account was opened due to the 'impossibility of obtaining a residence certificate in Qatar, where he would not have to pay tax'.
He then goes on to explain that Guardiola did not deposit the funds in Spain because they feared that, without a residency permit in Qatar, the Spanish