Spooks from the National Intelligence Agency (NIA) in South Africa have been drafted in to help ensure the integrity of the country's school-leaving tests and carry out background checks on invigilators and markers.
Nearly half a million pupils recently started sitting the exams, which were last year plagued by fraud last year.
Some of South Africa's nine education departments have called in the services of the NIA, while others have brought in private security companies, or both.
Cheating by 61 teachers in Mpumalanga province last year resulted in an investigation of some 2,000 exam scripts and delayed the release of the results.
The national education department requires all provinces to report on how they are ensuring the integrity of the exams.
Tommy Makhode, ministerial spokesman, said some provinces "indicated that they had entered into security agreements with the NIA". "From what we've seen so far, the system appears to be intact and provinces will continue to be vigilant," he said.
KwaZulu-Natal, which has been free of exam fraud since 1996, is one of the provinces using both the NIA and security companies.
Spooks have conducted background checks on invigilators, moderators and markers and security guards have been delivering papers to schools on the morning they are written.
Several exams in the UK had to be changed last year after 24 GCSE, AS and A-level papers were stolen from Harrow Park tutorial college in north London. Pages from maths and chemistry papers were also passed on to the Daily Mirror.
The Home Office was unable to confirm or deny M15 involvement in exam security. But the Qualifications and Curriculum Authority said it had never met with M15, although it had been in discussions with Scotland Yard.