Former Barcelona president Sandro Rosell defended Tuesday the legality of Brazilian striker Neymar's contract during questioning by a Spanish court which is investigating possible tax crimes.

Rosell told Madrid's National Court, Spain's top criminal court, that all contracts related to Neymar's 86-million-euro ($117 million) signing last year "were done perfectly" and respected the law, a judicial source said.

Investigating judge Pablo Ruz in June issued a summons for Rosell and the football club, through its legal representatives, to appear in court as tax crime suspects over the Neymar deal.

The Spanish taxman lost out on up to 11.8 million euros in total, according to the summons.

A tax office report cited by the judge listed lost revenues of 2.4 million euros in 2011; 6.8 million euros in 2013 and as much as 2.6 million euros in 2014.

Rosell resigned from Barcelona in January as he faced legal action accusing him of misappropriation of funds for not disclosing the destination of all the money spent on bringing the 22-year-old Brazilian forward to the club last summer.

The club then revealed that the entire cost of the operation including Neymar's signing bonus, commissions, marketing deals, a donation to the player's foundation and other agreements totalled 86.2 million euros -- far above the 57 million euros first announced by Barcelona.

As a result Barcelona were then indicted for alleged tax fraud linked to the signing.

The Catalan giants made a voluntary tax payment of 13.5 million euros in February over the signing to avoid the club's name being tarnished.

During his court appearance on Tuesday Rosell said he "did not read all the small letters" of the Neymar contracts when the player was signed but after being summoned by the judge he reviewed all their terms and concluded they were legal.

Barcelona managing director Antoni Rossich also argued before the court on Tuesday that Neymar's contracts respected the law.

The club said in a statement after the court hearing that it had to act "with extra prudence and confidentiality" during Neymar's signing due to the "exceptional interest of other clubs in the player".

"Barcelona trusts and expects that these statement sin court will make it clear that it acted correctly at all time," the statement added.

In April, the Spanish league said it believed there was nothing irregular about the Neymar signing.

The Neymar transfer case was started by one of Barca's own club members, Jordi Cases.

He accused Rosell of misappropriation for not declaring publicly that 40 million of the 57.1 million figure initially quoted by Barca was paid to N&N, a company controlled by the player's parents.