He hasn't returned the emerald! (4)

I believe the answer is:

emil

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'he' is the definition.
(I've seen this before)

I can't explain the remainder of the clue.

(Other definitions for emil that I've seen before include "German boy" , "- - Zatopek, Olympic runner" , "French boy's name" .)

I've seen this clue in the Evening Standard.

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