Investigative

google

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late Middle English: from Latin investigatio(n- ), from the verb investigare (see investigate).

wiktionary

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investigate +‎  -ive

etymonline

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investigative (adj.)

"of or pertaining to investigation, curious and deliberative in research," 1803, from Latin investigat-, past-participle stem of investigare (see investigation) + -ive. Journalism sense is from 1951.