Story highlights One victim's brother says report is "completely wrong"

An investigation finds that the two girls, who were cousins, committed suicide

There is no evidence of rape, sexual assault or murder, the investigators say

An initial report had found the girls were raped and strangled, but it was later questioned

The sight of two dead teenage girls hanging from a mango tree in northern India in May shocked India and the world beyond.

Now, a government investigation has concluded that the two cousins, aged 14 and 16, were not gang raped and murdered as police initially said, but took their own lives.

Officials from India's Central Bureau of Investigation (CBI) said they didn't know why the girls had committed suicide but suggested it might be because the elder girl was under pressure from her family over a relationship with a man from a different caste -- who was one of those initially accused in the case.

"Her family didn't approve of this and she was under pressure. Being an immature girl living in a very conservative part of India, it must have been hard for her," a top-level official, who declined to be named, told a news conference on Thursday.

Forensic experts also had determined that the mango tree from which the girls were found hanging was the easiest in the grove to climb, and that the girls would have been able to do so, he said.

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The brother of one of the victims said the CBI report was "completely wrong" and said the families would continue to seek justice.

"They say the older girl had an affair with the accused and committed suicide, then why did my sister, the younger girl, have to commit suicide?" Virender Siakia told CNN.

"Also, how can they climb 12 foot up a tree without a chair or ladder to help them? This is all about caste, we think the CBI is under political pressure."

Police said in May that two girls had both been from the lower rungs of India's entrenched caste system that has long defined a person's place in society.

Conflicting reports

The girls went missing after apparently going outside to relieve themselves during the night as they had no toilet at home.

During the initial stages of the investigation, an autopsy report confirmed the two girls had been raped and strangled.

The teenagers' families filed a complaint accusing a group of men of rape and murder.

But forensic reports commissioned by federal investigators subsequently said the girls were not raped, and charges against the five men were dropped.

The cousins' deaths came after the brutal gang rape of a girl on a public bus in New Delhi in December 2012.

That incident energized activists and women generally, with government officials promising action to ensure that girls and women feel safe.

Mayawati Kumari, a high-profile female politician in Uttar Pradesh state where the girls lived, said on Thursday that the investigation was conducted "in haste" and she did not agree with the report.

The All India Democratic Women's Association said on Twitter that it didn't approve "the theory" that the two girls killed themselves.

Law enforcement agency: No male DNA found

The findings of the investigation were outlined at a news conference Thursday.

Kanchan Prasad, a spokeswoman for the CBI, said they were based on about 40 scientific reports.

Investigators found no stress marks or traces of semen on either of the bodies, and no trace of male DNA was found on the girls' clothes or anywhere on their bodies, she said.

The report will be submitted to Badaun Court next week, she said, and there will be no further investigation by the CBI.

All five of the accused men were released on bail after the decision not to file charges, and they remain on bail. The court will decide whether it will take the case forward.

Lie-detector tests were conducted on the accused and the relatives. While the results of the accused were fine, those of the relatives indicated deception, she said.

A top-level CBI official, who took questions from journalists but declined to be named, said it was "medically proven that it was a suicide."

Asked about the discrepancy between the initial autopsy and subsequent forensic reports, the official said that the investigators involved in the first autopsy report were not experts and had mistakenly concluded there had been a sexual assault.