"Commonly used agrochemicals or pesticides have been ruled out as the cause of mortality", a statement, posted on Facebook read.
Elephant carcasses have been tested for traces of nine pesticides and chemicals known to have affected wildlife in the southern African country.
Encephalomyocarditis, a viral disease that causes inflammation of the cardiac muscle, infections with several other pathogens, and malnutrition were likewise deemed implausible. The ministry added that poisoning, including naturally occurring toxins, was still being investigated.
In July, hundreds of elephant carcasses were found in the country’s northwest region. Botswana contains the world's largest elephant population of about 130,000 mammals, according to media.