While Alexander Zverev continues to proceed through the draw at the French Open in Paris, where he is among the favorites for the men's singles title, his assault trial is taking place around 1,000 kilometers (620 miles) away in a drab and indistinct courtroom in Berlin.

In Paris, the reigning Olympic champion is battling to win the one thing that has eluded him in tennis: a Grand Slam title. He beat Alex de Minaur in Wednesday's night match to reach the tournament semifinals.

In Berlin, Zverev's assault trial represents a very different battle, one whose outcome could have major implications for his own career, as well as the way tennis handles domestic abuse cases in the future.

DW answers some of the key questions surrounding the trial.

What is Zverev accused of?

Zverev is charged with "physically abusing a woman and damaging her health during an argument." The woman is his ex-girlfriend, who is also the mother of his child.

He faces a trial at the Berlin criminal court because he is challenging a penalty order and fine of €450,000 ($488,000) that were handed down by a judge last October.

A document published by the court ahead of the trial revealed that the alleged incident took place in May 2020 in the stairwell of a Berlin apartment building. Zverev is said to have "briefly strangled his then-partner by the neck with both hands," causing her "shortness of breath and considerable pain."

The document also emphasized that "in view of the circumstances, it is expressly pointed out once again that the presumption of innocence applies until a final conviction."

What has happened so far at the assault trial?

The trial opened on May 31, with Zverev's legal representatives outling an aggressive defense strategy. The proceedings were then adjourned before his ex-girlfriend, who is appearing as a co-plaintiff, was able to give her testimony in public. 

The adjournment came after a request from Zverev's lawyers to have her testimony heard behind closed doors. 

After taking submissions from both sides, the sole presiding judge, Barbara Lüders, agreed to the request at the start of the trial's second day on June 3. Lüders explained that the ex-girlfriend "did not object" and said that even though Zverev is a public person, he has a right to privacy over likely revelations about the relationship and family matters.

It isn't yet clear whether other witnesses and experts will also be heard in private. 

The trial is scheduled to run over 10 non-consecutive days until July 19. It coincides with two major tennis tournaments: the French Open and Wimbledon. However, Zverev is only required to attend court if Lüders compels him to do so, and that hasn't happened yet.

How has Zverev responded?

Zverev has previously dismissed the allegations against him as "complete bull***t" and said that "anybody that has semi-standard IQ levels knows what this is all about," without elaborating further.

Last October, when the penalty order was issued, his lawyers from the law firm Schertz Bergmann called the proceedings "scandalous" and claimed "there can be no question of a fair trial."

On a media day ahead of the French Open, Zverev confirmed he had no plans to be present at the trial.

"I believe in the German system," he said. "I do know what I did, I do know what I didn't do. That's, at the end of the day, what's going to come out, and I have to trust in that. I do believe that I'm not going to lose this procedure. There's absolutely no chance I am."

What are the possible outcomes for Zverev?

Zverev's decision to contest his penalty order comes with certain risks. Lüders could indeed acquit him, but — in the case of a guilty verdict — could equally impose a harsher punishment.

According to the German Criminal Code, "whoever physically assaults or damages the health of another person incurs a penalty of imprisonment for a term not exceeding five years or a fine."

But while it remains legally possible for Zverev to receive a jail term, a court spokesperson told DW in January that this would be "highly unlikely" given the nature of the penalty order.

Lüders' verdict may not be final, as it can be appealed by either side to a higher court.

Why is Zverev still allowed to play tennis?

The governing body of men's tennis, the ATP Tour, doesn't currently have a domestic abuse policy. This is in contrast to other sports, particularly in the United States.

Despite this, the ATP's code of conduct states that a player can be suspended if they are "charged with a violation of a criminal or civil law of any jurisdiction." So far, the ATP has chosen not to enforce this.

The French Open director, Amelie Mauresmo, told media in Paris that "as long as the trial isn't finished and there isn't a decision, he's considered innocent and so that's why he's allowed to be part of the draw."

Meanwhile, Zverev's sponsors — with the exception of Rolex — have stood by him and maintained their silence. However, if Zverev is found guilty, they, like the ATP, will come under further pressure to finally act.

Previous abuse allegations against Zverev

This is not the first time Zverev has been accused of domestic abuse.

In social media posts and interviews in 2020 and 2021, another ex-girlfriend, Olya Sharypova, claimed he was violent toward her multiple times, in Monte Carlo, New York, Geneva and Shanghai. She said she feared for her life.

However, Sharypova didn't press criminal charges, and in January 2023, the ATP closed its own investigation into the matter, citing "insufficient evidence."

Welcoming that decision at the time, Zverev said: "From the beginning, I have maintained my innocence and denied the baseless allegations made against me."

This story was updated on June 6, 2024 to reflect Alexander Zverev's progress at the French Open and the latest developments in his trial. It was first published on May 27, 2024.