spy; covert operative; agent provocateur
Usually refers to a person secretly working for an organization, state, or faction to gather information, infiltrate, influence, sabotage, or provoke trouble. Common in news, security, and political contexts.
The police detained a foreign operative.
An agent infiltrated the meeting to confuse the opposition.
Literal or occupational use for someone engaged in making or constructing things. This is much less common in modern everyday Japanese than 作業員, 職人, or 建設作業員, and may appear in compounds or job-title-like wording.
If a job posting says “metalwork worker,” it refers to a worker who makes metal products.
That country sent covert agents into its neighboring nation.
He had infiltrated the company as a covert agent.
The man was arrested on suspicion of being a covert agent.