# investigation

/ˌɪnˌvɛstəˈɡeɪʃən/ (US) · /ɪnvˌɛstɪɡˈeɪʃən/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/investigation
Updated: 2026-05-02

## Definition

a careful and detailed search for facts or the truth about something. You use this when the police, a scientist, or a reporter looks into a problem to find out what happened.

For teachers: a formal or systematic examination or research into a subject or incident. Often implies a search for evidence or the cause of a specific event.

## Examples

- The police started an investigation into the robbery.
- The fire department launched a full investigation to determine if the blaze was started by faulty wiring.
- Following the whistle-blower's testimony, the committee initiated a thorough investigation into the company's financial records to uncover any evidence of systemic fraud.

## Pitfalls

- Not "an investigation about the crime" but "an investigation into the crime" — While 'about' is sometimes used, 'into' is the standard and more precise preposition for a formal examination.

## Usage notes

- Often takes the preposition 'into' to specify the subject being examined.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.