MADRID: Barcelona star Lionel Messi has been named as a suspect in a tax fraud probe and summoned to appear in court, a spokesman for the public prosecutor's office in Barcelona said Thursday.

The 25-year-old four-time World Player of the Year and his father Jorge Horacio are accused of defrauding the Spanish tax authorities of more than four million euros ($5 million, #3.4 million).

Spanish financial crimes prosecutors filed papers with a court in Catalonia, northeastern Spain, on June 12 accusing Messi and his father of cheating on income related to the use of his image from 2006-2009.

Messi and his father aimed to deceive the state by ceding Messi's image rights to companies based in tax havens such as Belize and Uruguay so they would pay no tax in Spain, according to the prosecutor's complaint.

“The judge today accepted this complaint and has summoned Messi and his father to appear in court on September 17. They are considered suspects,” the spokesman for the public prosecutor's office in Barcelona, Jose Miguel Company, told AFP.

The striker and his father have fiercely denied any wrongdoing and Barcelona president Sandro Rosell has said the club has no doubt that the superstar was innocent of tax avoidance.

“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 in an English-language statement released on his Facebook account the day prosecutors filed their complaint.

The accusations of tax fraud are a huge blow to the prestige of Messi, who has long been seen as a more humble figure than most top-class footballers -- in particular his fierce Real Madrid rival Cristiano Ronaldo.

The prosecutor's complaint also alleged Messi and his father 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.

They acted with “total opaqueness” towards the Spanish authorities, it added.

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.

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

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