Ereira directed a documentary called From the Heart of the World - The Elder Brother's Warning (1990) for the British Broadcasting Corporation.

In this film he documented his unique visits to the Kogi people of Colombia, an indigenous ('Indian') ethnic group which survived attempts by the Spanish conquerors to destroy them by retreating high up into the mountainous area of the Sierra Nevada, where they now live.

Ereira regards the Kogi as unique amongst indigenous peoples in the Americas in that they have managed to retain their traditional culture almost entirely intact.

Aluna is the sequel documentary to The Heart of the World: Elder Brother's Warning and was made by an indigenous film crew and the Kogi Mamos in collaboration with Ereira.

In 2004 he also presented, wrote and produced a 6-part documentary series on the kings and queens of England for UKTV History.