Two judges have come under fierce criticism in Argentina after they reduced a convicted child abuser's sentence almost by half, ruling his six-year-old victim had already been traumatised through earlier abuse.

Mario Tolosa saw his sentence cut from six years to 38 months in the newly publicised ruling from last year, after judges ruled he should not, in legal terms, be considered "gravely outrageous" because the boy "was making a precocious choice" of his sexuality, apparently a reference to homosexuality, the Associated Press has reported.

The Argentine Federation of Lesbians, Gays, Bisexuals and Trans have now demanded the judges be removed from the bench, saying the ruling placed the victim "in the position of a suspect".

Other attorneys have also criticised the ruling, which dominated the news in Argentina on Monday.

One of the two judges, Horacio Piombo, however has defended their decision.

The judge gave interviews to Radio La Red and television station Todo Noticias in which he said before the boy was molested by Tolosa, the child had already suffered “the initiation by his father into the worst of worlds, leading him to depravation.”

He said that as a result of that experience with the father, the child had shown "signs of a transvestite conduct, of conduct we had to take into account."

He also said the ruling, which is nearly a year old, had been leaked in an attempt to discredit him and his colleague Benjamin Ramon Sal Llargues.

He said the boy's father had been jailed by another court and the child's mother abandoned him.

The family of the boy meanwhile has said it will appeal the ruling before the Supreme Court.

A woman who identified herself as the child's aunt said: "He raped a child and they say he's innocent because the child is gay."

Politicians have also taken to social media to express their thoughts on the case.

Interior Minister Florencio Randazzo, who is running for the presidency, wrote on Twitter the ruling was "an embarrassment."

He wrote: "It's repugnant to say that the presumed sexual orientation of an abused six-year-old boy is a reason to reduce the sentence of the abuser."

The father and the family have not been identified by media to protect the child.