The prime minister speculated about the origin of COVID-19 during a speech to an environmental summit on Monday.
He said it was "the product of an imbalance in man's relationship with the natural world".
The PM continued: "Like the original plague which struck the Greeks I seem to remember in book one of the Iliad, it is a zoonotic disease.
"It originates from bats or pangolins, from the demented belief that if you grind up the scales of a pangolin you will somehow become more potent or whatever it is people believe, it originates from this collision between mankind and the natural world and we've got to stop it."
But Beijing's foreign ministry spokesman Zhao Lijian said "careful and meticulous" studies were needed to discover the origin of the coronavirus outbreak.
Read more at Sky News.