File photo of Rajesh and Nupur Talwar with Aarushi Talwar.

The film "Talvar", based on the 2008 Aarushi Talwar murder , has generated new buzz around India's most gripping whodunit. For the first time in seven years, the officer who led the initial CBI investigation into the case has said that he believes Aarushi's parents Rajesh and Nupur Talwar are innocent.Then joint director Arun Kumar - played by actor Irrfan Khan in the film - insists that there is no evidence to suggest that Rajesh and Nupur Talwar, currently in Dasna jail near Delhi, killed their daughter."There are several reasons why I think that,'' said Mr Kumar, who is now posted with the Central Reserve Police Force. "First and foremost is that the killers couldn't have assumed that the body of Hemraj would not have been found on the first day.''Hemraj's body was found by the Noida police a day after Aarushi's, from the roof of the same building."Forensic samples were never collected and if they had been, then the case could have been solved very easily," said Mr Kumar.No one from the CBI has ever spoken about the fact that two of its investigation teams contradicted each other - the first team said the Talwars' helps killed Aarushi, but the second CBI team said the parents killed Aarushi after finding her with Hemraj.It was Mr Kumar's theory that the Talwars' help Krishna killed both Aarushi and Hemraj because Hemraj had objected to Krishna and Rajkumar assaulting the teen.The theory was junked after a new CBI director, Ashwani Kumar, took over.When asked whether rivalry between the two directors led to the flip flops in the case, something that has also been shown in the film, Mr Arun Kumar refused to comment. He said after the second team completed its investigation, he was asked about his opinion in a meeting. "I told them that there was no evidence to link the Talwars to the crime," he said, adding that it was then that the closure report was filed.When NDTV pointed out that later, CBI officer AGL Kaul still told a court that the parents did it, Mr Arun Kumar said: "He has since died so I don't want to speak about him, but the officer should not have gone beyond what was decided by the authority, which is the CBI director.''