Barcelona's Argentina forward Lionel Messi and his father have been accused by Spanish tax authorities of defrauding the state of over £3 million.
The World Player of the Year and his father Jorge allegedly filed fraudulent tax returns for the years 2006, 2007, 2008 and 2009, according to a spokesman for the prosecutor's office for tax crimes in Catalonia.
A Barca spokesman did not immediately respond to a request for comment.
Messi, who will be 26 this month, is one of the world's highest-paid athletes with a salary of just over £12m a season, according to Forbes magazine.
On top of his Barca wages, he pulls in a similar amount in endorsements from sponsors including adidas, PepsiCo and P&G and he is 10th on Forbes' latest list of top-earning athletes.
Messi came on for the final half-hour of Argentina's World Cup 2014 qualifier against Ecuador in Quito on Tuesday which ended in a 1-1 draw.
Messi has released a statement denying any wrongdoing after reports claiming the Spanish tax authorities are investigating allegations he and his father defrauded the state of four million euros (£3.4million).
The 25-year-old Argentinian, currently on international duty in South America, swiftly insisted he had done nothing wrong, though, in a statement on his official Facebook page.
It read: "We have just known through the media about the claim filed by the Spanish tax authorities.
"We are surprised about the news, because we have never committed any infringement.
"We have always fulfilled all our tax obligations, following the advice of our tax consultants, who will take care of clarifying this situation."