The Central Bureau of Investigation (CBI) sent samples obtained by police in the northern Uttar Pradesh state, where the incident had happened, to a special DNA fingerprinting facility in southern India for re-examination after it took over the case, an official source told CNN Tuesday.
"(Test) results didn't show the girls were sexually assaulted," said the CBI source, who requested anonymity. "There were also several discrepancies in the post-mortem report."
But with the latest evidence appearing to rule out rape, investigators, for now, have dropped plans to file charges against the five.
"The CBI is not going to file the charge-sheet against them as of now. However, we are not giving them clean chit either," CBI spokeswoman Kanchan Prasad said.
She said the investigation into the girls' killing would continue.
Under Indian law, suspects in custody for serious crimes become eligible to apply for bail if formal charges are not filed against them in the trial court within 90 days.
Left hanging from tree
Five people, including two police officers, were arrested after the girls -- who were cousins aged 14 and 16 -- were left hanging from the branches of a mango tree in a remote village in Budaun district on May 27.
A photo from the village showed the body of one girl, dressed in a green tunic and pants, hanging from the tree. A large group of people, many of them young children, were gathered around the grisly scene.
The girls' families filed a complaint accusing three brothers of rape and murder.
Police said an autopsy confirmed the girls had been raped and strangled.
The case caused widespread revulsion in India and beyond, reminding people about the brutal gang-rape of a girl on a public bus in Delhi in December 2012.
Back then, a 23-year-old physiotherapy student was traveling home from a movie with a male friend when at least five other men on the bus dragged her to the back of the bus and then beat up her friend.
The men took turns raping the woman as the bus drove around the city for almost an hour, police said at the time. The two friends were then dumped by the side of the road, with the young woman later dying from her injuries.
That incident energized activists and women generally, with government officials promising action to ensure that girls and women feel safe.