"It was alleged in the case that the accused persons had adopted a unique engine-bogie system or method of cheating in MPPMT-2012 by engaging intelligent students from out of Madhya Pradesh as solver candidates for allowing copying of their answers by the beneficiaries or bogie candidates and also manipulation of digital data and OMR answer sheets of accused candidates by the said persons for passing these candidates in MPPMT-2012," CBI Spokesperson RC Joshi said in a statement.
The agency had booked 587 accused on July 31, 2015 in connection with the case.
It had chargesheeted 592 accused on November 23, 2017 before a special CBI court in Bhopal.
"During further investigation, the CBI found the real identities of impersonators, traced absconders etc. In the said supplementary chargesheet, 54 accused persons related to manipulation of digital data and OMR answer sheets and 19 accused related to impersonation were chargesheeted," Joshi said.
He said it was alleged that 19 accused candidates had deliberately left the ovals (OMR sheet markings) of 120 to 130 questions blank on their respective OMR answer sheets during the examination.
The digital data of the OMR sheets was manipulated by accused officials of the Madhya Pradesh Professional Examination Board, known as Vyapam, who subsequently blackened the correct answers to illegally pass these candidates, Joshi said.
"Untampered data of accused candidates was also recovered and it showed that these candidates had filled up less answer circles. In conspiracy with these candidates, their guardians and middlemen, the said Vyapam officials manipulated digital data and OMR answersheets of these candidates to enhance their marks and to illegally pass them in MPPMT-2012," he added.
The CBI has alleged that the then principal system analyst of Vyapam, Bhopal had prepared an excel sheet containing the names of the accused candidates, their sponsors, the roll numbers, the amounts paid or to be paid, marks and categories etc. and the said excel sheet was recovered by the agency.
The CBI had named 16 accused candidates for alleged impersonation.
It ascertained the real identities of these accused using innovative techniques, including scrutinising the data of the candidates of PMT examinations from 2010-2014 of some states and AIPMT, and cross-checking the financial database of the credit cards, debit cards, bank accounts used for the submission of fee, Joshi said.
"The agency also rummaged through social media profiles created by using the mobile phone numbers, email IDs, which were filled in the application and counselling forms of impersonators; database of photos of more than 18 lakh aspirant PMT students, MBBS students as well as registered doctors collected from medical colleges, coaching centres, MCI, medical education directorates of some states etc. and database along with photos of untraceable or unidentified candidates scrutinised through experts and photo-matching exercise," Joshi said.