Police said the preliminary medical examination of Tahir Ahmed Mir had indicated that he was not a minor.
"Doctors have said that the accused is around 20 years old," a police officer said.
A controversy had arisen about the age of the accused after a private school issued a date of birth certificate that said the minor was born on July 23, 2009.
Police suspected the genuineness of the certificate from the very beginning. They have lodged an FIR against the principal of the private school.
Police said the special investigation team (SIT) set up to probe the heinous crime would fast-track the investigation.
Kashmir has erupted with shock and outrage against the rape of the three-year-old.
The crime was allegedly committed when Muslims in the area were busy breaking their daily fast during the ongoing holy month of Ramadan.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)