In 2009 Ms Samudio made the first allegations to police that she was pregnant with Fernandes' child, and that the star and others kidnapped her and tried to force her to terminate the pregnancy.
She refused and the child was born healthy. But the model disappeared in June 2010 and has not been found.
In December 2010 Fernandes was found guilty of Ms Samudio's initial accusations and is serving a prison sentence of four years and six months.
He is now being tried a second time, this time on charges that he ordered his ex-girlfriend's death. Investigators said the player was behind a scheme that lured the 25-year-old woman from Rio de Janeiro to a ranch in the neighbouring state of Minas Gerais.
There she was allegedly held against her will by Fernandes' accomplices, killed and quartered, and her remains fed to dogs on the property.
The first day of the murder trial in Minas Gerais was marked by high drama, with lawyers for two of Fernandes' alleged accomplices walking out after arguing with the judge.
Those charged with Ms Samudio's kidnapping, murder and the hiding of her body include Dayanne Rodrigues, Fernandes' wife; Fernanda Castro, a lover; and Luiz Romao, a former police officer. All have denied the charges.