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before the police could inquire the criminals had destroyed all the cles
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Before it could be inquired by the police - This is incorrect English. Inquire is not a transitive verb.
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Before the police could inquire, the criminals had destroyed all the clues.

This is in active voice .

Passive form : Before it could be inquired by the police, all the clues had been destroyed by the criminals .
 AlpheccaStars's reply was promoted to an answer.