CHENNAI: The cash-for-marks racket at Anna University boosted scores of a student in one paper (in April/ May 2017 exam) from 5 to 77 after re-evaluation, in a manner that would seem perfectly legal, but by exploiting loopholes in rules.This answer sheet from the April/ May 2017 exam is part of evidence collected by directorate of vigilance and anti-corruption ( DVAC ), which has booked former controller of examinations G V Uma and nine others for taking money to rig answer sheets. Tens of thousands of students may have paid to pass, the investigators suspect.The university re-evaluation rules state that if the re-evaluation marks are 15 marks more than the original, a second re-evaluation is to be done. The marks obtained in the central evaluation, first re-evaluation and second re-evaluation are compared, and the ‘best’ among the two ‘most consistent marks’ is taken as the ‘true’ score. In this case, the student’s marks changed from 5 to 45 after the first re-evaluation, a change of 40 marks from the original. Since the difference in marks was more than 15, the paper was sent for a second re-evaluation as per rules. After the second re-evaluation, the student was given 77 marks.Now, the difference between marks of the first re-evaluation and the second re-evaluation was 32, which is lesser than the difference between the primary valuation and the first re-evaluation, which was 40. So, 45 and 77, which were nearer to each other than 5 and 45, were considered ‘consistent marks’. Of the two, as per the rule, 77 was considered the ‘true mark’ as it was higher. Similar anomalous increase of marks was found in several papers. When university officials, suspicious of the great improvement in marks, gave this marksheet to a third external examiner. This new examiner gave the student 8 marks.“This means that the fraud happened not at the central evaluation, but it was a well-planned conspiracy during the re-evaluation,” said a highly-placed source in the university. Officials said many other answer sheets were found to have been similarly tampered with. What’s worse, the central evaluator, who would have given the correct marks, ended up being debarred for no mistake of his, said the source.DVAC is investigating Uma’s role in influencing examiners at the re-evaluation centre in Tindivanam. The other accused in the case include two assistant professors of Government College of Engineering, Tindivanam , the re-evaluation centre and seven other examiners.Uma did not respond to TOI’s calls on Friday. In a telephonic interview to TOI on Thursday, she denied all charges and said she was being targeted for trying to reform the examination system.