A Chilean man insisted on Monday he did not kill his Japanese ex-girlfriend Narumi Kurosaki in 2016, at the start of his appeal against his murder conviction in a French court.
Nicolas Zepeda was sentenced in April last year to 28 years in jail for the murder of Kurosaki, then aged 21, in December 2016.
Her body was never found.
The appeal trial opened exactly seven years after Kurosaki was last seen.
"I did not kill Narumi," Zepeda, 32, said in French, speaking in court in the eastern town of Vesoul.
"I contest with all my might the things I am accused of," said Zepeda, who has learnt French in prison.
"It has been a real nightmare," he said in front of a packed courtroom, which included the victim's mother and two sisters.
"I think of her family's enormous grief, which I carry with me all the time," he added, visibly moved.
In February, the appeal was delayed after the defendant's lawyer was changed at the last moment.
Sylvie Galley, who represents Kurosaki's family, told reporters: "If the family is here today, it's for one and only one reason -- to honour Narumi's memory".
"The family has come without any hope of revelation, confession or truth from Nicolas Zepeda," she added.
Galley said that the family had already mourned Narumi and that maintaining hope "would be extremely destructive".
The defendant's father, Humberto Zepeda, said he wanted to see his son exonerated at the end of the "new trial".
"No-one can say with certainty today that Narumi is dead," he said. "Scientifically, it's impossible," he added.
"This is the 21st century. A country as developed as France cannot sentence a person to 28 years on the basis of a hypothesis. It's not possible."
Renaud Portejoie, a lawyer for Zepeda, said he hoped the new trial would help "change the situation".
"The trial ahead of us is difficult, impossible some would say, but we are ready to do our outmost to ensure that this second trial is different from the first," he said.
He has commissioned a new psychiatric examination and may call on new witnesses.
Kurosaki, a brilliant scholarship student, arrived in the eastern French city of Besancon that summer to learn French.
She disappeared on December 4.
Zepeda, with whom she had broken up a year earlier, was the last person to see her alive.
The Chilean has admitted spending the night with Kurosaki in December, claiming he ran into her by chance.
Several witnesses reported hearing "screams of terror", although none called the police at the time.
Some of Kurosaki's friends received strange messages in the following days from her social networking accounts, which police believe were sent by Zepeda.
He was extradited from Chile to France in 2020.
Prosecutors said at the first trial that Zepeda was unable to deal with the couple's break-up, travelling to Besancon to kill Kurosaki in her student dorm room before dumping the body in the forests of the rugged Jura region.
They pointed to evidence from witnesses, telephone records and geolocation of the car Zepeda hired.
