A senior CBI official said that an FIR was registered against A.K. Srivastava, who was a Deputy Director in the FSL's facility in Rohini, Delhi, when the reports were submitted.
In all three cases, forensic reports were given in favour of the accused. However, the CBI's re-examination proved that the reports had been tampered with.
Apart from Srivastava, his colleague at the FSL at the time the forensic reports were allegedly tampered with, L. Babyto Devi, has also been booked by the CBI in the case.
The re-examination had been ordered on the basis of orders by the Delhi High Court in August 2018.
As per the CBI's FIR, one of the rape cases was registered at Badarpur police station in Delhi in 2013.
A trial court had acquitted the accused on the basis of the tampered report submitted by the FSL. While a three-member board that undertook the re-examination on the basis of the High Court's orders found that the report submitted by Srivastava did not conform to actual scientific findings.
The second case pertains to the charges of sodomy and murder in an FIR registered at Mahindra Park police station of Delhi in 2012.
Findings in the report submitted by Srivastava and Devi were found contrary to scientific evidence, it said.
In the second case of rape registered at Samaypur Badli police station in 2012, data submitted by the FSL did not match with the subsequent report prepared by the Central Forensic Science Laboratory.
"Enquiry has prima facie established that reports/opinion given by Ms L Babyto Devi and Dr AK Srivastava in the above mentioned cases are inconsistent with the reports given subsequently by experts of FSL, Rohini and experts of CFSL CBI, New Delhi," the FIR stated.
The accused have been booked under relevant sections of the Prevention of Corruption Act, 1988 and under sections 201 and 218 of the Indian Penal Code.
( With inputs from IANS )