An undated file photo shows Diego Garcia, the largest island in the Chagos archipelago and site of a major United States military base in the middle of the Indian Ocean leased from Britain in 1966.

Chagos Islands: Britain an 'illegal colonial occupier' after failing to hand back control

The Foreign Office does not recognise Mauritius' claim to sovereignty over the islands, one of which is home to a US airbase.

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