Cover from Diego Gracia, Chagos, B.I.O.T (British Indian Ocean Territory)

I think this letter not send from B.I.O.T area, but from Singapore.
Coz B.I.O.T Post have an office in Singapore...
Any one can advise me?

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Dear Fren,

Could you please advise why you sent this letter?

Thx & Brgds,
Jefferson

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