The chemistry paper of class 10 was leaked ahead of time in Sukkur, Ghotki and Ubaro on Wednesday morning, reported 24NewsHD TV channel.
The copy of paper was shared in WhatsApp groups, creating a wave of joy among the students.
However, the teams of the education department and the raiding teams also failed to stop the copying.
The candidates were busy using their mobile phones openly.
The Sindh government's negligence and poor performance in exams are being heavily criticized on social media.