Former Barcelona and Brazil footballer Dani Alves went on trial on Monday charged with sexually assaulting a woman in the bathroom of a nightclub in the city in 2022.

The 40-year-old defender was arrested in January last year and has been held on remand in the city since then.

Alves initially denied any sexual encounter with the woman whom he said he did not know.

He later said he had consensual sex with his accuser, adding that he had denied it originally to protect his marriage. The case has attracted significant attention not only because of Alves' profile but because sexual assault is a dominant political theme in Spain, more notably still following the alleged non-consensual kiss Spanish football federation chief Luis Rubiales planted on the lips of a female player following her team's Soccer World Cup win last August.

In Spain, a claim of rape is investigated under the general accusation of sexual assault and convictions can lead to jail time of between four and 15 years.

A Spanish public prosecutor is seeking a nine-year prison term and for Alves to pay damages worth 150,000 euros ($163,215) to the woman.

Alves appeared before the court on Monday. His mother and brother were seen arriving at the court while his lawyer and the victim's lawyer were also seen entering the building. A panel of three judges will oversee the trial which is expected to last three days at Barcelona's highest court.

It will include the testimony of Alves, the alleged victim and about 30 other people. The alleged victim will testify from behind a screen and in the recording of the trial her voice and image will be distorted to protect her identity.

The 2016 gang-rape of a teenager during the San Fermin bull-running festival led to the toughening of sexual violence laws in Spain and triggered national soul-searching on the topic that continues to this day as gender violence rates remain high.

Alves is one of the most successful footballers in history, having won more than 40 trophies for his country and clubs like Barcelona. Following his arrest, he was fired by Mexico's Pumas UNAM.