Messi and his father Jorge Horacio Messi were accused of fiddling the taxes.

Barcelona superstar Lionel Messi denied stunning allegations Wednesday that he and his father engaged in tax fraud worth more than four million euros ($5 million).

The 25-year-old Argentina international and four-time World Player of the year expressed shock at the accusation by Spanish financial crimes prosecutors.

"We are surprised about this news because we have never committed any infringement," the striker said in an English-language statement released on his Facebook account.

"We have always fulfilled all our tax obligations, following the advice of our tax consultants who will take care of clarifying this situation," Messi said.

The player said he had just heard of the move against him through the media.

Messi and his father Jorge Horacio Messi were accused of fiddling the taxes in a legal filing lodged by financial crimes prosecutor Raquel Amado, a copy of which was obtained by AFP.

"It is all a mistake, you have to speak about this to the tax experts and lawyers who need to clear it up," the player's father told Spanish sports daily AS.

"I don't understand what is going on. I don't manage these matters, I am resident in Argentina," he said.

The father said he had not spoken to his son about the reports. "I don't need to since it is a mistake. Why would I shock him?"

The allegations were filed in a court in Catalonia, where Messi is resident, but judges could yet refuse to let it proceed, a judicial source told AFP.

If it were to go ahead, it would represent a huge blow to the prestige of Messi, who has long been seen as a more humble figure than most top-class footballers and particularly his Real Madrid rival Cristiano Ronaldo.

Messi's achievements on the field have made him one of the most marketable sportsmen in the world, however.

Indeed, the Argentine was ranked 10th amongst Forbes' list of sports stars' incomes this month with an annual $21m from endorsements alone.

The player and his father are accused of three crimes of defrauding the state of taxes related to income from the use of his image from 2006-2009.

The allegations center on tax declarations made in 2007, 2008 and 2009.

The striker and his father aimed to "deceive" the taxman by ceding Messi's image rights to companies based in tax havens such as Belize and Uruguay, the prosecutor's complaint said.

They drew up deals related to his image rights in Britain and Switzerland, ensuring that the income went straight to the tax havens without any tax being paid, it said.

Messi and his father acted with "total opaqueness" toward the Spanish authorities, the filing said.

The complaint lodged with the court in Gava, near Barcelona, accused them of defrauding the state of 1.06 million euros in 2007, 1.57 million euros in 2008, and 1.53 million euros in 2009.

The father was accused of being the brains behind the scheme, allegedly setting it up in 2005 before his son turned 18 on June 24 of that year.

The prosecutor said Messi later agreed with his father's tactics so that he would avoid any taxes on income from the use of his image rights during the period.

The income related to his image rights included contracts with FC Barcelona, Banco Sabadell, Danone, Adidas, Pepsi-Cola, Procter & Gamble and Kuwait Food Company.

Messi's net income from image rights amounted to 2.56 million euros in 2007, 3.82 million euros in 2008 and 3.80 million euros in 2009, the complaint said.