Let Us Return: The Story of the Chagos Islanders. 2015 documentary directed by Andy Marsh (15 minutes).
How the U.S. Stole an Island. 2021 video by Johnny Harris (10 minutes).
Stealing a Nation: How the UK/US Stole the Diego Garcia Island. 2004 TV documentary written and directed by award winning journalist John Pilger (56 minutes).
Camp Justice. 2016 Pivot TV documentary. Watch on iTunes, YouTube, or Amazon (25 minutes).
60 Minutes. 2003 CBS News investigation (12.5 minutes).
For more, see this excellent list compiled by Dr. Richard Dunne.