Neymar appears in court over 2013 transfer

Spanish prosecutors are seeking a two-year prison term and a 10 million euro ($A16m)  fine for Neymar.

They are also seeking a five-year jail term for former Barca president Sandro Rosell and an 8.4m euro ($A13m) fine for the club.

Neymar arrived at court wearing sunglasses and a black suit and tie. His mother and father, who also is his agent, were among those with him.

The case centres on the claim made by Brazilian investment firm DIS, which owned 40% of the rights to Neymar when he was at Santos, that it lost out on its rightful cut from the player's transfer because the value of the deal was understated.

DIS has demanded a much heavier five-year jail term for Neymar, fines worth 149m euros ($A230m) in total, and for the player to be disqualified from playing for the length of any sentence handed down by the judge.

Along with Neymar, 30, the defendants include his parents, representatives of the two clubs, former Barca presidents Josep Maria Bartomeu and Rosell, and former Santos president Odilio Rodrigues.

The defendants, who have denied wrongdoing, sat near each other to hear the opening arguments in the trial that is expected to last until the end of the month.

Neymar left about two hours after arriving. The judge allowed him to leave early as he had played the night before. He is expected to testify on Tuesday.

Law firm Baker McKenzie, who is defending Neymar and his family, said in a statement they would argue the Spanish courts "lack jurisdiction to prosecute the Neymar family" because the transfer involved a Brazilian national in Brazil.

Neymar, a key member of the Brazil team that will be heading to the World Cup in Qatar next month, lost an appeal over the case in Spain's High Court in 2017, clearing the way for the trial.

The transfer has already led to one case. In 2016, Barcelona paid a fine of 5.5m euros ($A8.6m) to Spanish authorities with the club acknowledging it made "an error in the fiscal planning of the player's transfer."