Telltale thief (5)

I believe the answer is:

sneak

I believe this is a double definition.

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

'thief' is the second definition.
(sneak thief is a kind of thief)

(Other definitions for sneak that I've seen before include "thief" , "peach" , "To go stealthily" , "Go furtively - inform on another child" , "Prowl" .)

I've seen this clue in The Telegraph.

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