Veerasami, who is lodged in the Central Jail here, was brought to the hospital under tight security, after which senior doctors carried out the necessary tests, including potency test, they said.
Veerasami was later taken back to the jail.
Meanwhile, 18 inmates of the closed hostel were accommodated in two city hostels and efforts are on to find out the parents or relatives of these children, police said.
The girls, aged 10 and 11, and inmates of the hostel in Pollachi, about 35 km from here, were bodily lifted and raped on the terrace of an adjacent building reportedly at knifepoint by two persons who approached them in the wee hours of June 12 on the pretext of asking for water.
They were rescued and admitted to Pollachi Government Hospital by police, after the inmates, one of whom was thrashed by the rapists, informed hostel management, who in turn alerted police.