One examines fake requisition when drug goes missing (10)

I believe the answer is:

inquisitor

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'one examines' is the definition.
(an inquisitor examines or questions someone)

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for inquisitor that I've seen before include "Ecclesiastical interrogator" , "Exacting investigator" , "Torquemada, for example" , "Ruthless examiner" , "One prize crossword" .)

I've seen this clue in The Telegraph.

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