Italy's Angela Carini left her boxing match with Algerian athlete Imane Khelif in protest in less than a minute on Thursday.
"I couldn’t carry on. I have a big pain in my nose and I said, ‘Stop’. It’s better to avoid keeping going. My nose started dripping from the first hit," Carini said after the 66kg fight on Thursday.
"It could be the match of my life but, in that moment, I had to safeguard my life, too."
Khelif was disqualified from the 2023 women's world championships in New Delhi after effectively failing a gender test.
But Khelif is able to fight at the Paris Games, because Olympic boxing is run by a different body.
The International Boxing Association (IBA), formerly the AIBA, was in charge of the world championships but is no longer recognized by the International Olympic Committee due to governance issues.
The IOC says Khelif, who was born a woman, is listed as a woman on her passport and fulfills the eligibility requirements as a cisgender. IOC spokesman Mark Adams also made the point that Khelif had lost against other women over the years.
Discussing a separate issue at the daily IOC news conference, comments from the head of the IOC’s Safe Sport Unit Kirsty Burrows raised eyebrows among journalists given the boxing furore.
"When we talk about safe sport, we're referring to physically and psychologically safe athletic environments, so both mental health and safeguarding," she said.
Carini, with a suspected broken nose, said: "I train with my brother. I’ve always fought against men, but I felt too much pain today."
Her coach Emanuele Renzini added: "I don't want to pre-empt the IOC and I know it's a difficult subject, but this fight was unfair."
The Algerian Olympic Committee condemned the criticism of Khelif.
"These attempts at defamation based on lies are completely unfair, especially at a crucial moment. We are all behind you, Imane. The whole nation is behind you and is proud of your achievements."
