Kottayam: A PSC examination in Alappuzha was cancelled on Saturday after invigilators at the centre where the exam took place mistakenly distributed the afternoon session’s question paper during the morning exam.The mix-up occurred at Lajnathul Muhammadiya School where 166 candidates appearing for the morning exam (10-11:35am) received the paper meant for the afternoon’s PSC Company Board Last Grade Servants exam, scheduled at the same centre from 1.30pm to 3:05pm. The error surfaced only after the morning exam ended, when candidates compared question papers with those from other centres and then returned to alert school authorities.PSC officials subsequently cancelled the afternoon’s SSLC-level general test for various posts and added that the morning session went off without incident at all other centres. A special re-exam will be held for candidates affected at the Lajnathul Muhammadiya centre.Saturday’s exams were part of a multi-stage recruitment test for SSLC-qualified candidates, held in morning and afternoon sessions due to time constraints. Preliminary findings suggest the error occurred when an invigilator opened a question paper packet without checking its colour code — forenoon (FN) envelopes are marked brown and afternoon (AN) envelopes green. Exam-duty staff, however, said the confusion arose because both sessions’ papers were supplied together at the centre.Departmental action will be taken against those found responsible, and police have sought clarification from the school administration. The remaining third and fourth stages of the SSLC-based general test are scheduled for Aug 1. DYFI staged a protest march to the PSC district office over the lapse.