The CCC says the activist had been forced into a vehicle by armed men on Saturday while campaigning for a party candidate ahead of the 9 December polls.
The by-elections are being held following what the party said was an “illegal and fraudulent” recall of its members.
Last month, over a dozen opposition MPs lost their seats after a man, who declared himself as the party’s interim secretary-general, said the MPs were no longer members.
The CCC now says the recall of its elected members had resulted “in the death of our change champion”.
The death of the activist follows a pattern of abductions of opposition politicians and human rights activists in Zimbabwe.
The CCC has blamed state agents for the violence against its members – which the ruling Zanu-PF party has denied.
