A huge haul of bones found in a small, dark chamber at the back of a cave in South Africa may be the remnants of a new species of ancient human relative.

Explorers discovered the bones after squeezing through a fissure high in the rear wall of the Rising Star cave, 50km from Johannesburg, before descending down a long, narrow chute to the chamber floor 40 metres beneath the surface. 

The entrance chute into the Dinaledi chamber is so tight - a mere eight inches wide - that six lightly built female researchers were brought in to excavate the bones. Footage from their cameras was beamed along 3.5km of optic cable to a command centre above ground as they worked inside the cramped enclosure.