But now, the CBI describes this as a genuine mistake and not a cover-up. The CBI says the doctor who took Aarushi's vaginal samples forgot to enter this in his records. Then, the pathologist who preserved the sample used a slide which had another sample.
Interestingly, the doctor who made that mistake is Dr Richa Saxena, who is a friend of Aarushi's mother, Nupur Talwar.
Two months after Aarushi's death, from the Noida police, when the CBI took over the case, they learnt the sample existed. They sent the slide to their own lab in Delhi. Experts here said there were two vaginal samples mixed together. One was Aarushi's.
The CBI then sent the sample for further testing to a forensic lab in Hyderabad. The findings there are radically different. There's just one sample, and it's not Aarushi's. Experts here are convinced that the sample was switched.
The CBI may have to explain in court why it isn't prosecuting the doctors who mishandled Aarushi's sample. But sources in the agency say they'll stand by their investigation, including their theory that despite any evidence to prove this, they believe that Aarushi was killed by her father's dental assistant, Krishna and his associates.
Meanwhile, the CBI has set up a new team to handle the controversial investigation. It will be headed by Joint Director Javed Ahmad and Neelabh Kishore.