The 20-year-old Iraqi, known as Amir A, is under the tightest of security in Vienna’s notorious Josefstadt jail.
A prison source told media in the Austrian capital the man was despised by fellow inmates for what he was alleged to have done.
The boy”s mother, named as Dunja, said the accused, who entered the country on September 5 last year and was said to have claimed he carried out the attack because he had not had sex in four months, could not be believed.
The alleged victim”s mother was also revealed to have once been an asylum seeker herself.
Dunja, said told Austrian media she had urged her five children to be as welcoming to would-be refugees as people in the central European country had been to her when she arrived there from Serbia in the 1990s.
She said: “My son cried himself to sleep every night after the attack and could not close his eyes without taking antidepressants. He tried not to let me see him crying, it broke my heart.
“I know that the physical wounds will heal, but the wounds to his soul may never heal. I don”t want the man to be deported, I want him to be jailed because I have heard what they do to child sex attackers in jail.
“I want him to experience everything in jail that child sex attackers can experience from the other convicts. And then I want him deported.”
The boy, 10, was hospitalised after the incident, which took place in a cubicle at the Theresienbad pool in Vienna on December 2.
The mother said: “I come from Serbia, and I spent five years living in a Caritas home together with people from many different nations.
“You certainly can”t call me a racist, but to try and defend himself in that way is just monstrous.
“It”s like me saying I”m going to go to a bank tomorrow and rob it because I don”t have enough money for my five children.”