Special observer Ajay Pal Sharma toured South 24 Parganas during phase two polling, warning troublemakers of "appropriate treatment" to prevent voter intimidation.
Party leaders accused Sharma of overstepping his role, while CM Mamata Banerjee claimed no state police officials were visible during polling.
Sharma's proactive measures in Diamond Harbour, Abhishek Banerjee's turf, sparked controversy ahead of the Assembly elections.