BARCELONA, SPAIN -- Brazilian soccer star Dani Alves went on trial Monday, a year after he allegedly sexually assaulted a young woman at a Barcelona nightclub.

The 40-year-old Alves, a former Barcelona player, has been in pre-trial custody for over a year since he was detained for allegedly sexually assaulting the woman on the night of Dec. 31, 2022. He denies any wrongdoing.

Dressed in a white dress shirt and jeans, Alves took a seat in the courtroom after arriving in a police van. His mother was also present at the Barcelona courthouse. After a short recess when the courtroom was emptied, Alves' mother blew her son a kiss and made a heart-shaped gesture as Alves was escorted in handcuffs back inside.

State prosecutors are seeking a nine-year prison sentence for Alves if convicted while the lawyers representing his accuser want 12 years.

The court ordered the accuser's testimony on Monday be behind closed doors with no media access and no image of her can be taken to protect her identity. That decision came after a video circulated on social media last month that allegedly identified the woman.

A screen was placed between the accuser and Alves when she testified and the court ordered the video recording of her testimony be pixelated and her voice distorted as preventative measures to ensure her privacy in case of a leak.

In testimony given to state prosecutors last year, the woman said she met Alves late at the Sutton nightclub in one of Barcelona's upscale neighbourhoods after midnight. She accompanied him into a VIP area and into a private bathroom where he allegedly slapped her, used insulting language and raped her, according to her testimony given to prosecutors.

Two women, a friend and a cousin, who accompanied the woman to the nightclub testified that when they saw her after she exited the bathroom she was distraught and told them that Alves had "hurt her badly." Workers at the nightclub also gave testimony.

Alves will testify on Wednesday, the trial's last day.

Before he was indicted by an investigative judge in August, Alves' lawyers unsuccessfully tried to discredit testimony by his accuser and other witnesses by presenting security camera footage from the nightclub. The court has said that any alleged flirting should not "in any way justify an eventual sexual assault."

Alves has modified his defence several times.

At first, he denied having ever seen the woman when he went dancing on the night in question.

Upon his arrest, he denied any sexual contact with her, only to admit three months later to a sexual encounter that he said was consented to by the woman. He said he had been trying to save his marriage by not admitting to the sexual encounter initially.

In the only interview Alves has given since his arrest, he told Spanish newspaper La Vanguardia in June that "my conscience is clear about what happened that early morning. ... What happened and what did not happen. And what did not happen is that I forced that woman to do what we did."

Alves, whose legal name is Daniel Alves, has changed attorneys three times. At the trial he is represented by Ines Guardiola, who was hired in October.

Alves was arrested on Jan. 20, 2023 after answering a police summons during a visit to Spain. A court ordered him to be jailed after analyzing the initial police investigation and hearing testimony from the alleged victim, witnesses and the player himself.

Three days after his arrest, Alves was transferred by officials for safety reasons to the Brians 2 prison about 45 minutes northwest of Barcelona. He has been there ever since.

Alves' requests for bail were denied because the court considered him a flight risk, despite his offer to hand over his passport and wear a tracking device. Brazil does not extradite its own citizens when they are sentenced in other countries.

The alleged victim is represented by Ester Garcia, a specialist in prosecuting sex crimes.

The trial is before a three-judge panel presided over by magistrate Isabel Delgado. Twenty-eight witnesses were scheduled to give testimony on Monday and Tuesday before the court hears Alves, along with experts, on Wednesday.

Under Spain's 2022 sexual consent law, the crime of sexual assault takes in a wide array of crimes from online abuse and groping to rape, each with different possible punishments. A case of rape can carry a maximum sentence of 15 years.

Alves has been ordered to set aside 150,000 euros (US$162,000) to pay his alleged victim if he is found guilty and ordered to pay damages.

Alves' arrest shattered his image of a charismatic winner with a lengthy and successful career.

He won major titles with elite clubs including Barcelona, Juventus and Paris Saint-Germain. He also helped Brazil win two Copa Americas and an Olympic gold medal at age 38. He played at his third World Cup, the only major title he's not won, in 2022.

The right back was a key part of Barcelona's golden years while playing from 2008-16. He won the Champions League three times with the Catalan club, which he briefly rejoined in 2022.

Alves' contract with Mexican club Pumas was terminated immediately after his arrest.