Barcelona  star Lionel Messi  and his father Jorge have been summoned to appear in court on September 17 in order to provide evidence against recent tax fraud allegations.A complaint, signed by prosecutor Raquel Amado, was filed with the courthouse in the Gava district of Barcelona last week and it has now been decided that there is enough evidence to summon the Argentine.The Spanish tax authorities claim that the prolific attacker and his father have avoided paying the charges due from sales of the 25-year-old's image rights by operating through companies based outside of the country, totalling over €4 million between 2006 and 2009.Messi stressed last week that he is innocent and unaware of committing any infringements."We have learned through the media about the claim filed by the Spanish tax authorities. We are surprised about this news, because we have not committed any infringement," a statement from the 25-year-old read."We have always fulfilled all of our tax obligations, following the advice of our tax consultants, who will take care of clarifying this situation."The attacker's fiscal and legal advisor Angel Juarez, meanwhile, insisted that they had not heard anything yet when the news broke last week, while adding that they were ready for any legal battle."Neither we nor our client have received any notification from the prosecutor in relation to what has been reported," a statement signed by Juarez read."As his legal and fiscal council, we will take all the appropriate legal action against the complaint of the prosecutor and we are confident that justice will prevail."Messi's camp is yet to react to the latest developments.Under Spanish law, Messi could face a maximum penalty of six years in prison if found guilty.