Police have arrested six suspects and feared that their "very cruel" method of poaching in the 14,651 sq km Hwange National Park could threaten hundreds of animals as the poison would contaminate the entire ecological system.
Two rotting carcasses of dehorned elephants were found, while 17 tusks, valued at $120,000, were recovered from the suspects, Xinhua reported citing a report in the Chronicle newspaper.
Authorities are still searching for more carcasses while working out plans to contain the disastrous impact on the environment.
Zimbabwe is home to more than 100,000 elephants and about 700 rhinos, whose survival is often threatened by rampant poaching.
Hwange, located in northwest part of the country near Botswana, Namibia, and Zambia, is home to one of the largest population of elephants in the world.
Officials estimated that 69 elephants were killed by poachers in the area between May and August.