"SPFW has just received the news of the death of model Tales Soares, who suddenly took ill during the Ocksa show," the organisation said in a statement, without giving a cause of death.
Medics immediately attended to Soares in front of horrified onlookers, according to local media reports.
He started foaming at the mouth as paramedics tended to him on the catwalk before rushing him to hospital, where he was pronounced dead.
Following the model's death, footage began to emerge on social media of Soares collapsing shortly after making a swift turn on the runway.
During the clip, Soares can be seen walking down the runway in front of hundreds of spectators before turning around as he approached the top of the catwalk.
As he turned at the end of the catwalk, the model appeared to stagger and soon fell face-first onto the runway.
Daily Folha de S. Paulo reported that Soares tripped on his shoelace and fell. According to the paper, people in the crowd initially thought his fall was part of a performance.
"We offer our sincere condolences to Tales' family," it said, while label Ocksa said on Instagram its entire team was "shocked" by the death of Soares, who was signed to Base MGT modelling agency.
Model Tales Soares is taken from the catwalk by paramedics after he collapsed. Photo / AP
Tales - who also worked under the name Tales Cotta - was with Brazilian modelling agency Base MGT.
A spokesperson for the agency said: "We emphasise that the model always had exemplary behaviour. He was not a newcomer; he has already paraded in other editions of both SPFW and other important fashion events.
"Tales never presented or complained about health problems. He had a healthy diet (he was a vegetarian), did not use illegal substances and was in full condition to participate in the parade. And we ask for respect at this moment of deep sadness."
News agency Terra reported that concerns had been raised about the availability of vegetarian food at the event, which meant he may have gone a long time without eating.
