NEW DELHI/LUCKNOW (Reuters) - Indian federal investigators are analyzing a forensic report that found that two teenage girls, earlier believed to have been raped before they were murdered, were not sexually assaulted.
Images of the cousins, still hanging from a mango tree in a village in the northern state of Uttar Pradesh, shocked the world in May and threw light on an enduring culture of sexual and caste violence in India.
Based on testimony from relatives of the girls, who belonged to a low-caste community, three brothers were quickly arrested. Two policemen were also held on suspicion of trying to conceal the crime.
But investigations, first by regional police and then by the Central Bureau of Investigation (CBI) - India's counterpart to the U.S. FBI - failed to substantiate the relatives' accounts.
The new report from India's Centre for DNA Fingerprinting and Diagnostics (CDFD) further complicates the case, as it contradicts an earlier post-mortem that concluded that the girls had been raped.
"We have come to know that the girls were not sexually assaulted," CBI spokeswoman Kanchan Prasad told Reuters on Friday, adding that the agency had asked a three-member medical board to review the report.
Even before the CDFD report surfaced, regional police had cast doubt on whether the girls had been sexually assaulted and instead suggested they could have been victims of so-called 'honor' killings.
A.L. Banerjee, a senior officer in the Uttar Pradesh police, reiterated that stance, telling Reuters that the preliminary investigation had raised suspicions about such killings.
"I had said very clearly that it's not a case of gang rape ... the media was not ready to listen to us. Instead they chose to start a media trial," Banerjee said in the state capital, Lucknow.
With the latest report ruling out rape, the victims' families have started questioning the investigation.
"I fail to understand what has transpired between the Uttar Pradesh police and the CBI - the entire findings are getting twisted," the father of one of the two victims told reporters.
A series of leaks, sourced to unnamed investigators, surfaced in the Indian press after the CBI took over the case in June. In one, newspapers reported that the suspects had passed lie-detector tests, while relatives of the victims had not.
The investigating agency declined to comment on such leaks.
Authorities last month considered exhuming the bodies for further examination, but heavy rainfall that inundated the burial area prevented them from doing so.
Prasad said the medical board that is assisting the CBI would now decide if there is a need to exhume the bodies now.
Controversy surrounding the killings had stoked political tensions between India's newly-elected prime minister, Narendra Modi, and the state government in Uttar Pradesh, India's most populous state.
For one, the surnames of four of the five suspects identify them as members of the same caste as state premier Akhilesh Yadav. Modi's nationalist party inflicted heavy losses on Yadav's party in the April-May general election.
Modi, who initially remained silent over the killings, spoke out against rape during his first Independence Day speech a week ago, saying India was shamed by increasing reports of sexual violence against women and girls.
The number of reported rapes in India rose by 35.2 percent to 33,707 in 2013 from the previous year, according to the National Crime Records Bureau.
India toughened its rape laws after the gang-rape and murder of a 23-year-old student on a moving bus in New Delhi in 2012 led to nationwide street protests.
Still, sex crimes against young girls and women remain widespread. Females from poor and marginalized communities are often among the victims, activists say, while many such crimes go unreported or are not properly investigated.
Writing by Aditya Kalra; Editing by Douglas Busvine/Jermey Gaunt