Initial reports stated that Soares tripped on his long shoe straps, however, he was later seen foaming at the mouth, prompting concerns it could have been an epileptic fit.
The model's agent, Rogério Campaneli, from MGT Base agency said to FocusOn News: "This has been a shocking series of events that we're trying hard to piece together. But everything happened so suddenly and unexpectedly.
"Doctors suspect that Soares might have had a congenital problem. From videos, they believe he died on the catwalk.
"It was all so fast: he kissed a friend behind the scenes who was following him, walked out confidently as usual, then suddenly stumbled, lost his footing and fell."
Soares' sister, Gabrielle Gomes, told Brazilian media, G1 that she wasn't aware of any medical condition her brother had, and stated that he had regular medical checkups.
She said: "Me and my mother [Heloisa] spoke to Tales by video call before the parade and he said he was well and said he had just finished eating a carrot.
"We're very scared and devastated by what happened. He was very healthy, ate healthily and exercised every day. He did cross fit and yoga."
Soares' family were watching the show from Manhuaçu, in Minas Gerais state when they noticed that he hadn't returned to the catwalk, and transmission was then cut off.
A traumatised Gabrielle said: "My mother called to find out what was going on, they said that Tales had been taken ill and hospitalised and shortly after, the organisation called again and said he had died."
The cause of death is still to be determined and the family are hoping the results will bring them closure.
