A former chief of Spain's tax system has said the controversial deal that took Neymar to Barcelona was done in an unusual way.
Spanish judge Pablo Ruz is investigating whether a fraud took place in the transfer, with current Blaugrana president Josep Maria Bartomeu and former club chief Sandro Rosell facing charges of hiding the full transfer cost paid to Santos in summer 2013 and thereby not paying the full taxes due.
Rosell and Bartomeu have both maintained they did nothing wrong in the complex deal that saw the Brazilian persuaded to spurn interest from Real Madrid and move to the Camp Nou.
Barcelona did, however, make an advance extra payment of 13.5 million euros in February 2014, when the court began investigating the deal closely.
Ignacio Ruiz Jarabo, the director of Spain's Agencia Tributaria (tax authority) between 1998 and 2001, told Radio Barcelona it appeared to him that the way the deal was structured -- including a number of side payments to companies run by Neymar's father -- meant less tax was initially paid.
"All I know is what has come out in the media," Ruiz Jarabo said. "But the way the transfer was done is not usual. The result was to pay less taxes than were due.
"In fact, the club itself has made an extra advance payment, although that is not necessarily an admission that there were taxes they should have paid."
Ruiz Jarabo also said the authorities' treatment of Barca's Lionel Messi, who has appeared in court charged with irregularities in his tax filings, looked mistaken.
"I am not saying there is persecution," he added. "But I do believe that footballers are victims of what in my opinion is an error or mistaken criteria."
The retired civil servant spoke again about allegations made in a book published in 2011, when he claimed Real Madrid president Florentino Perez once threatened an all-out strike in response to a push to audit all the clubs.
"When the inspection began, the clubs immediately saw this was something serious and that it was being coordinated," Ruiz Jarabo said. "We had reliable information that Real Madrid president Florentino Perez asked the finance minister that the inspections be stopped.
"He did so in no uncertain terms, warning that if this did not happen then he would halt the competition."
Ruiz Jarabo also retold a story of when Madrid returned from having won the 1998 Intercontinental Cup in Japan and Florentino intervened to stop customs officials from looking closely at the gifts the players had bought.
"The players were stopped at the airport and asked 'do you have anything to declare?,'" he said. "Florentino responded: 'Yes, that they are champions of the world.'"