Arrest Greek character involved in racket (6)

I believe the answer is:

detain

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'arrest' is the definition.
(detain can mean to arrest or hold)

I can't explain the rest of the clue.

(Other definitions for detain that I've seen before include "Keep (someone) held in custody" , "Stop" , "Keep in custody or delay" , "Ate din (anag.)" , "Keep in official custody" .)

I've seen this clue in The Sun and The Times.

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