I come from Bulgaria and we have a proverb that says (translated one to one) "You're searching calf under the ox." which literally means that I am searching for something that might not exists.
Example usage: "Stop interrogating Mary already, she's obviously not guilty, don't search for calf under the ox."
Is there idiom with same meaning in English as well?
Best Answer
"On a wild goose chase" might work.
Cambridge Dictionary gives this definition:
The phrase finder has an article on the history of the phrase. Here's an extract: