Elite cops ordered to arrest most members of gang? (6,6)

I believe the answer is:

secret police

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'elite' is the definition.
The answer and definition can be both groups as well as being singular nouns.
Maybe they are linked in a way I don't understand?

I don't understand the rest of the clue.

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(Other definitions for secret police that I've seen before include "Anti-subversion force" , "NKVD, perhaps" , "Undercover lawmen" .)

I've seen this clue in The Telegraph.

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