The General Directorate of National Security said 57 people were arrested in 15 towns across the kingdom in a cash-for-answers scandal that saw other test responses sent to students via SMS.
Those detained were accused of providing "written answers to students in exchange for money," the GDNS said.
The investigation "found numerous web pages and social media sites used for leaking test answers."
According to news site Medias 24, two pages of an exam paper were posted on Facebook the night before the test.
Opposition groups have called for the minister's resignation.
More than half a million students took their high school leaving exams last week in Morocco, the results of which will be announced on June 24.
