Hundreds of students have been caught writing or drawing obscenities, including racist remarks and lewd drawings, on A-level and GCSE exam papers,
Figures released by exam watchdog Ofqual on Thursday reveal the number of students receiving penalties for doing so has more than doubled since 2007 to 422 candidates.
Most of the penalties were issued by the OCR examining board and appeared in Ofqual's malpractice report on this year's summer exam period.
Students caught writing the obscene comments are liable to be disqualified from the exam as well as receiving disciplinary action from their school.
The figures also report the most common type of malpractice was candidates bringing unauthorised material into exams.
More than 1,700 penalties were issued, with mobile phones making up 34% of the total figure.
Some students were disqualified for using electronic devices during exams, whereas others had marks docked or were given warnings after bringing them into assessment centres.
But the overall number of penalties issued - 3,678 - has decreased by 11% since summer 2010.