Microscopic traces of wood ash have been found alongside animal bones and stone tools in a cave in South Africa.
The evidence of fire has been dated to a million years ago by a team, led by the University of Toronto and Hebrew University of Jerusalem.
They say it has become the earliest known evidence of the controlled use of fire by human ancestors.
The traces were discovered in the Wonderwerk Cave in South Africa, a huge cavern near the edge of the Kalahari Desert.
It has been the scene of previous excavations, which have uncovered an extensive record of human occupation.
Analysis of a layer of sediment in the cave revealed plant remains that had turned to ash and burned bone fragments.
Michael Chazan, University of Toronto anthropologist, said: “The analysis pushes the timing for the human use of fire back by 300,000 years, suggesting that human ancestors as early as Homo erectus may have begun using fire as part of their way of life. The control of fire would have been a major turning point in human evolution.
“The impact of cooking food is well documented, but the impact of control over fire would have touched all elements of human society. Socialising around a campfire might actually be an essential aspect of what makes us human.”
The controlled use of fire allowed our ancestors to cook, stay warm and protect themselves from predators..
However, many scientists argue that while there is wide evidence for the controlled use of fire beginning about 400,000 years ago, earlier evidence could be the result of the opportunistic use of natural fires.