All deaths must be registered in the country where the person died.  You will need documents about yourself and the person who has died, including for example, the full name, date of birth and passport number of the person who has died. 

The local authorities will need to be told if the person suffered from an infectious condition (such as Hepatitis or HIV) so they can take precautions against infection. You do not have to register a death at the British High Commission, but by doing so, you can get a UK death certificate and a permanent copy of it will always be available in English in the UK.