interrogator vs questioner

interrogator and questioner both are nouns.

Word	Noun	Adjective	Verb	Adverb
interrogator	Yes	No	No	No
questioner	Yes	No	No	No

As nouns, questioner is a hypernym of interrogator; that is, questioner is a word with a broader meaning than interrogator:

Other hypernyms of interrogator include asker, enquirer, inquirer, querier.

interrogator (noun)	questioner (noun)
a questioner who is excessively harsh	someone who asks a question